Patent Application
20160257975
Fatty acid and fatty acid derivatives (such as fatty acid methyl esters (FAME), fatty alcohols, fatty amines, etc.) are important precursors to manufacturing many consumer products, industrial chemicals and fuels. For example, fatty acids and fatty acid derivatives are used to make detergents, cleaners, plastics, paper, paints, lubricants, waxes, coatings and surfactants. They can also be used as flavor and fragrance agents. Currently, fatty acids and fatty acid derivatives are produced from oleochemical (plant and animal fats) or petrochemical sources. In general, the fatty acids derived from oleochemical sources have aliphatic chains with an even number of carbons, whereas fatty acids derived from petrochemical sources have aliphatic chains with an odd number of carbons.
Both oleochemical and petrochemical fatty acids have significant shortcomings. Most notably, the feedstocks used to produce such fatty acids generally include a mixture of fatty acids of varying carbon chain lengths and may include a wide range of chain lengths, as well as saturated and unsaturated fatty acids.
Another short coming of oleochemical and petrochemical fatty acids is the wide fluctuation in the cost of the feedstocks. Oleochemical feedstock prices are extremely volatile and can significantly fluctuate from year to year and fluctuate among the various geographic regions. Since overall production costs are very sensitive to feedstock price, such volatility can significantly impact margins. Regarding petrochemical fatty acids, there is increasing acceptance that petroleum hydrocarbon supplies are decreasing, and as a result their costs are expected to continue to increase.
Finally, there is increasing concern regarding sustainability within the chemical industry, and there is a growing demand for chemicals produced from renewable resources. In fact, many chemical companies and their customers have implemented sustainability initiatives with a goal of replacing current chemicals such as petro-based chemicals with chemicals made from renewable sources. Such companies are seeking renewable chemicals that have minimal impact on product performance or characteristics, as well as minimal impact on downstream products and customers. There are even sustainability concerns within the oleochemical industry. Although many of the oleochemical fatty acids are derived from renewable resources, current industry practices do not manage the harvesting of these resources in a sustainable way. For example, there has been significant concern regarding deforestation in the production of palm oil, a primary source for oleochemical fatty acids.
In view of these shortcomings regarding petro-based and oleo-based fatty acids and fatty acid derivatives, interest has increased for developing and improving industrial microbial systems for production of chemicals and fuels using sustainable plant-based feedstocks. Such industrial microbial systems could completely or partially replace the use of petroleum hydrocarbons or oleochemicals for production of certain chemicals and products.
Numerous chemicals are produced through such microbial systems, ranging from antibiotic and anti-malarial pharmaceutical products to fine chemicals to fuels such as ethanol. However, there is still a commercial need for modified microorganisms that are adapted to produce fatty acids and fatty acid derived products, and in particular, fatty acid and fatty acid derived products that have a high concentration of a specific fatty acid chain length.
In one aspect the disclosure provides for a genetically modified organism comprising a heterologous nucleic acid sequence encoding a 3-ketoacyl-CoA synthase, a ketoacyl-CoA reductase, a hydroxyacyl-CoA dehydratase, or an enoyl-CoA reductase; and wherein said microorganism is capable of producing a fatty acid or fatty acid-derived product having a carbon chain length of C4 or greater. In some embodiments, the 3-ketoacyl-CoA synthase comprises NphT7. In some embodiments, the 3-ketoacyl-CoA synthase comprises an amino acid sequence of at least 70% homology to any one of SEQ ID NOs. 1-120. In some embodiments, the ketoacyl-CoA reductase is selected from the group consisting of a 3-ketobutyryl-CoA reductase, a 3-hydroxybutyryl-CoA dehydrogenase, a 3-ketovaleryl-CoA reductase, and 3-hydroxyvaleryl-CoA dehydrogenase. In some embodiments, the ketoacyl-CoA reductase comprises an amino acid sequence of at least 70% homology to any one of SEQ ID NO 183 and SEQ ID NO 271. In some embodiments, the hydroxyacyl-CoA dehydratase is selected from the group consisting of a 3-hydroxybutyryl-CoA dehydratase and an enoyl-CoA hydratase. In some embodiments, the hydroxyacyl-CoA dehydratase comprises an amino acid sequence of at least 70% homology to any one of SEQ ID NO 183 and SEQ ID NO 272. In some embodiments, the enoyl-CoA reductase is trans-2-enoyl-reductase. In some embodiments, the enoyl-CoA reductase comprises an amino acid sequence of at least 70% homology to SEQ ID NO 275. In some embodiments, the 3-ketoacyl-CoA synthase comprises a modified NphT7 polypeptide comprising one or more amino acid substitutions selected from the group consisting of a PDRP to HFLQ substitution for amino acids 86-89, F217A, F217E, F217G, F217I, F217L, F217M, F217P, F217S, F217T, F217V, F217W, G288S, G309S, I147A, I147C, I147D, I147E, I147F, I147G, I147H, I147K, I147L, I147M, I147N, I147P, I147Q, I147R, I147S, I147T, I147V, I147W, I147Y, V157F, V196G, and Y144L. In some embodiments, the 3-ketoacyl-CoA synthase comprises a modified NphT7 polypeptide comprising two amino acid substitutions selected from the group consisting of I147T and F217V, I147T and Y144L, I147T and V196G, I147F and F217V, I147M and F217V, I147S and F217V, I147T and HFLQ, I147T and V157F, I147T and F217G, I147T and F217A, I147T and F217L, I147T and F217I, I147T and F217M, I147T and F217P, I147T and F217S, I147T and F217E, I147S and F217G, I147S and F217A, I147S and F217L, I147S and F217I, I147S and F217M, I147S and F217W, I147S and F217S, I147S and F217E, I147S and F217K, I147F and F217A, I147F and F217L, I147F and F217I, I147F and F217M, I147F and F217P, I147F and F217E, I147M and F217G, I147M and F217A, I147M and F217L, I147M and F217I, I147M and F217M, I147M and F217P, I147M and F217S, I147M and F217E, and I147M and F217K. In some embodiments, the 3-ketoacyl-CoA synthase comprises a modified NphT7 polypeptide comprising three amino acid substitutions selected from the group consisting of Y144L, I147T, and F217V; I147T, F217V, and HFLQ; I147T, V147F, and F217V; and Y144L, I147T, and V157F. In some embodiments, the 3-ketoacyl-CoA synthase comprises a modified NphT7 polypeptide comprising one or more amino acid substitutions at a position selected from the group consisting of Ser84, Val114, Gly288, Ile194, Gly318, Thr85, Gln90, Val196, Tyr144, Phe159, Ile147, and Phe217. In some embodiments, the ketoacyl-CoA reductase is selected from the group consisting 3-ketoacyl-CoA reductase and 3-hydroxyacyl-CoA dehydrogenase. In some embodiments, the ketoacyl-CoA reductase comprises an amino acid sequence of at least 70% homology to any one of SEQ ID NO 183 and SEQ ID NO 271. In some embodiments, the hydroxyacyl-CoA dehydratase is selected from the group consisting of a 3-hydroxyacyl-CoA dehydratase and enoyl-CoA hydratase. In some embodiments, the hydroxyacyl-CoA dehydratase comprises an amino acid sequence of at least 70% homology to any one of SEQ ID NO 183, and SEQ ID NO 272. In some embodiments, the enoyl-CoA reductase is trans-2-enoyl-reductase. In some embodiments, the enoyl-CoA reductase comprises an amino acid sequence of at least 70% homology to SEQ ID NO 275. In some embodiments, the genetically modified organism further comprises a heterologous nucleic acid sequence encoding a thioesterase or a wax ester synthase. In some embodiments, the genetically modified organism further comprises a heterologous nucleic acid sequence encoding a termination enzyme that catalyzes the production of a fatty acid-derived product selected from the group comprising a fatty alcohol, a fatty aldehyde, a fatty alkene, a fatty amide, a fatty alkane, and a fatty diacid. In some embodiments, the thioesterase is an acyl-CoA esterase and the organism is capable of producing a fatty acid. In some embodiments, the thioesterase is selected from the group comprising tesA, ‘tesA, tesB, yciA, ybgC, ybfF, fadM, AtTE, CpTE, CperfTE, LpTE, and PA2801TE. In some embodiments, the thioesterase comprises an amino acid sequence of at least 70% homology to any one of SEQ ID NO 277, SEQ ID NO 278, SEQ ID NO 279, SEQ ID NO 280, SEQ ID NO 281, SEQ ID NO 282, SEQ ID NO 283, SEQ ID NO 284, SEQ ID NO 285, SEQ ID NO 286, SEQ ID NO 287, and SEQ ID NO 288. In some embodiments, the wax ester synthase is selected from the group comprising Maq1, Pcry1, Rjos1, and Abork1, and wherein said organism is capable of producing a fatty ester. In some embodiments, the wax ester synthase comprises an amino acid sequence of at least 70% homology to any one of SEQ ID NO 289, SEQ ID NO 290, SEQ ID NO 291, and SEQ ID NO 292, and wherein said organism is capable of producing a fatty ester. In some embodiments, the 3-ketoacyl-CoA synthase is NphT7; the keto-CoA reductase is selected from the group consisting of hbd and fadB; the 3-hydroxy-acyl-CoA dehydratase is selected from the group consisting of crt and fadB; the enoyl-CoA reductase is ter; and the thioesterase is selected from the group consisting of CpTE, fadM, PA2801TE, tesB, ybgC, ybfF, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a four or five carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of tesB and yciA. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, and NphT7 I147T, F217V; the keto-CoA reductase is fadB; the 3-hydroxy-acyl-CoA dehydratase is fadB; the enoyl-CoA reductase is ter; and the thioesterase is selected from the group consisting of AtTE, CpTE, CperfTE, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a six or seven carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of PA2801TE, tesB, and yciA. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, and synthase III; the keto-CoA reductase is selected from the group consisting of fadB and fabG; the 3-hydroxy-acyl-CoA dehydratase is selected from the group consisting of fadB, ech and ech2; the enoyl-CoA reductase is ter; and the thioesterase is selected from the group consisting of AtTE, CpTE, CperfTE, fadM, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA; and wherein the proteins encoded by the polynucleotides are capable of producing an eight or nine carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of PA2801TE, tesB, and yciA. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, synthase III, synthase IV, and synthase V; the keto-CoA reductase is selected from the group consisting of fadB and fabG; the 3-hydroxy-acyl-CoA dehydratase is selected from the group consisting of fadB, ech and ech2; the enoyl-CoA reductase is ter; and the thioesterase is selected from the group consisting of AtTE, CpTE, fadM, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a ten or eleven carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of tesB and yciA. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, synthase III, synthase IV, synthase V, and synthase VI; the keto-CoA reductase is selected from the group consisting of fadB, fabG, and fadJ, the 3-hydroxy-acyl-CoA dehydratase is selected from the group consisting of fadB, ech, and fadJ; the enoyl-CoA reductase is ter; and the thioesterase is selected from the group consisting of AtTE, CpTE, CperfTE, fadM, LpTE, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a twelve or thirteen carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of fadM, PA2801TE, tesA, tesB, and yciA. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, synthase III, synthase IV, synthase V, and synthase VI; the keto-CoA reductase is selected from the group consisting of fadB, and fadJ; the 3-hydroxy-acyl-CoA dehydratase is selected form the group consisting of fadB, and fadJ; the enoyl-CoA reductase is selected from the group consisting of ter, ydiO and fadE; and the thioesterase is selected from the group consisting of AtTE, CpTE, CperfTE, fadM, LpTE, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a fatty acid with a carbon chain length of at least fourteen carbons. In some embodiments, the thioesterase is selected from the group consisting of fadM, tesA, tesB, and yciA, and the proteins encoded by the polynucleotides are capable of producing a fourteen or fifteen carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of AtTE, CpTE, CperfTE, fadM, Pa2801TE, tesA, tesB, ybfF, ybgC, and yciA, and the proteins encoded by the polynucleotides are capable of producing a sixteen or seventeen carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of AtTE, fadM, tesA, tesB, ybfF, ybgC, and yciA, and the proteins encoded by the polynucleotides are capable of producing a sixteen or seventeen carbon fatty acid or fatty acid derived product. In some embodiments, the organism is capable of using acetyl-CoA as a primer and malonyl-CoA as the extender molecule to produce a fatty acid or fatty acid derived product have a carbon chain length selected from 4, 6, 8, 10, 12, 14, 16, 18 and 20. In some embodiments, the organism is capable of using propionyl-CoA as a primer and malonyl-CoA as the extender molecule to produce a fatty acid or fatty acid derived product have a carbon chain length selected from 5, 7, 9, 11, 13, 15, 17, 19, and 21.
In one aspect, the disclosure provides for a modified NphT7 polypeptide, comprising an amino acid sequence having at least 70% homology to SEQ ID NO:1 and one or more amino acid substitutions, deletions, or insertions, wherein the modified NphT7 polypeptide is capable of accepting an acyl-CoA substrate having a carbon chain length of C4 or greater. In some embodiments, the modified NphT7 polypeptide is capable of catalyzing a condensation reaction to condense an acyl-CoA substrate with a malonyl-CoA to produce a 3-keto-acyl-CoA having a carbon chain length of C6 or greater. In some embodiments, a modified NphT7 polypeptide comprises one or more amino acid substitutions selected from the group consisting of I147T, F217V, Y144L, V157F, G309S, G288S, a PDRP to HFLQ substitution for amino acids 86-89, I147F, I147M, I147Q, I147S, I147C, I147E, I147N, I147W, I147D, I147R, I147P, I147L, V196G, I147G, I147H, I147K, I147V, I147A, I147Y, F217G, F217A, F217L, F217I, F217M, F217T, F217P, F217S, F217E, F217L, F217W, and any combination thereof. In some embodiments, a modified NphT7 polypeptide comprises one amino acid substitution selected from the group consisting of I147V, I147F, I147M, I147Q, I147S, I147C, 1147E, I147N, I147W, I147D, I147R, I147P, I147L, I147G, I147H, I147K, I147A, I147Y, and F217V. In some embodiments, a modified NphT7 polypeptide comprises two amino acid substitutions selected from the group consisting of I147T and F217V, I147T and Y144L, I147T and V196G, I147F and F217V, I147M and F217V, I147S and F217V, I147T and HFLQ, I147T and V157F, I147T and F217G, I147T and F217A, I147T and F217L, I147T and F217I, I147T and F217M, I147T and F217P, I147T and F217S, I147T and F217E, I147S and F217G, I147S and F217A, I147S and F217L, I147S and F217I, I147S and F217M, I147S and F217W, I147S and F217S, I147S and F217E, I147S and F217K, I147F and F217A, I147F and F217L, I147F and F217I, I147F and F217M, I147F and F217P, I147F and F217E, I147M and F217G, I147M and F217A, I147M and F217L, I147M and F217I, I147M and F217M, I147M and F217P, I147M and F217S, I147M and F217E, and I147M and F217K. In some embodiments, a modified NphT7 polypeptide comprises three amino acid substitutions selected from the group consisting of (Y144L, I147T, and F217V), (I147T, F217V, and HFLQ), (I147T, V147F, and F217V), and (Y144L, I147T, and V157F). In some embodiments, a modified NphT7 polypeptide comprises one or more amino acid substitutions at a position selected from the group consisting of Ser84, Val114, Gly288, Ile194, Gly318, Thr85, Gln90, Val196, Tyr144, Phe159, Ile147, Phe217, and any combination thereof. In some embodiments, a modified NphT7 polypeptide comprises an I147T amino acid substitution. In some embodiments, a modified NphT7 polypeptide comprises an F217V amino acid substitution. In some embodiments, a modified NphT7 polypeptide comprises two or more amino acid substitutions, deletions, or insertions. In some embodiments, a modified NphT7 polypeptide comprises an I147T amino acid substitution and an F217V amino acid substitution. In some embodiments, a modified polypeptide of is isolated and purified.
In one aspect the disclosure provides for an isolated and purified polynucleotide encoding a modified NphT7 polypeptide of the disclosure.
In one aspect the disclosure provides for an isolated and purified polynucleotide comprising a nucleic acid sequence having at least 70% but less than 100% or about 100% homology or complementarity to SEQ ID NO:2, wherein the polynucleotide encodes a modified NphT7 polypeptide of SEQ ID NO:1 having one or more amino acid substitutions, wherein the modified NphT7 polypeptide is capable of accepting an acyl-CoA substrate having a carbon chain length of C4 or greater. In some embodiments, an isolated and purified polynucleotide of encodes a modified NphT7 polypeptide capable of catalyzing a condensation reaction to condense an acyl-CoA substrate with a malonyl-CoA to produce a 3-ketoacyl-CoA having a carbon chain length of C6 or greater. In some embodiments, an isolated and purified polynucleotide encodes a modified NphT7 polypeptide comprising one or more amino acid substitutions selected from the group consisting of I147T, F217V, Y144L, V157F, G309S, G288S, a PDRP to HFLQ substitution for amino acids 86-89, I147F, I147M, I147Q, I147S, I147C, 1147E, I147N, I147W, I147D, I147R, I147P, I147L, V196G, I147G, I147H, I147K, I147V, I147A, I147Y, F217G, F217A, F217L, F217I, F217M, F217T, F217P, F217S, F217E, F217L, F217W, and any combination thereof. In some embodiments, an isolated and purified polynucleotide encodes a modified NphT7 polypeptide comprising one amino acid substitution selected from the group consisting of I147V, I147F, I147M, I147Q, I147S, I147C, 1147E, I147N, I147W, I147D, I147R, I147P, I147L, I147G, I147H, I147K, I147A, I147Y, and F217V. In some embodiments, an isolated and purified polynucleotide encodes a modified NphT7 polypeptide comprising two amino acid substitutions selected from the group consisting of I147T and F217V, I147T and Y144L, I147T and V196G, I147F and F217V, I147M and F217V, I147S and F217V, I147T and HFLQ, I147T and V157F, I147T and F217G, I147T and F217A, I147T and F217L, I147T and F217I, I147T and F217M, I147T and F217P, I147T and F217S, I147T and F217E, I147S and F217G, I147S and F217A, I147S and F217L, I147S and F217I, I147S and F217M, I147S and F217W, I147S and F217S, I147S and F217E, I147S and F217K, I147F and F217A, I147F and F217L, I147F and F217I, I147F and F217M, I147F and F217P, I147F and F217E, I147M and F217G, I147M and F217A, I147M and F217L, I147M and F217I, I147M and F217M, I147M and F217P, I147M and F217S, I147M and F217E, and I147M and F217K. In some embodiments, an isolated and purified polynucleotide encodes a modified NphT7 polypeptide comprising three amino acid substitutions selected from the group consisting of (Y144L, I147T, and F217V), (I147T, F217V, and HFLQ), (I147T, V147F, and F217V), and (Y144L, I147T, and V157F). In some embodiments, an isolated and purified polynucleotide encodes a modified NphT7 polypeptide comprising one or more amino acid substitutions at a position selected from the group consisting of Ser84, Val114, Gly288, Ile194, Gly318, Thr85, Gln90, Val196, Tyr144, Phe159, Ile147, Phe217, and any combination thereof. In some embodiments, an isolated and purified polynucleotide encodes a modified NphT7 polypeptide comprising an I147T amino acid substitution. In some embodiments, an isolated and purified polynucleotide encodes a modified NphT7 polypeptide comprising an F217V amino acid substitution. In some embodiments, an isolated and purified polynucleotide encodes a modified NphT7 polypeptide comprising two or more amino acid substitutions. In some embodiments, an isolated and purified polynucleotide encodes a modified NphT7 polypeptide, comprising an I147T amino acid substitution and an F217V amino acid substitution. In some embodiments, an isolated and purified polynucleotide is RNA. In some embodiments, an isolated and purified polynucleotide is an mRNA. In some embodiments, an isolated and purified polynucleotide is a DNA. In some embodiments, an isolated and purified polynucleotide is a cDNA. In some embodiments, vector comprises a polynucleotide of the disclosure. In some embodiments, a plasmid comprises a polynucleotide of the disclosure.
In one aspect, the disclosure provides for a method of selecting a 3-ketoacyl-CoA synthase as a candidate for condensing a malonyl-CoA with an acyl-CoA having a carbon chain length greater than C2, comprising: identifying a 3-ketoacyl-CoA synthase polypeptide comprising an amino acid sequence having at least 70% but less than 100% or about 100% homology to SEQ ID NO:1; and selecting the 3-ketoacyl-CoA synthase as a candidate for condensing an acyl-CoA having a carbon chain length greater than C2 with a malonyl-CoA, if the 3-ketoacyl-CoA synthase comprises one or more features selected from the group consisting of an (A/G)GGSR sequence motif, lack of a STPDXPQ sequence motif, and solely hydrophobic residues in the substrate binding site. In some embodiments, the method comprises selecting at least two 3-ketoacyl-CoA synthases, wherein each synthase III occupies a different branch of a phylogenetic tree.
In one aspect the disclosure provides for a library of NphT7 homologs selected by a method of the disclosure.
In one aspect the disclosure provides for an isolated NphT7 homolog, comprising an amino acid sequence having at least 70% but less than 100% homology to any one of SEQ ID NOs. 1-120.
In one aspect the disclosure provides for an isolated polynucleotide encoding a selected 3-ketoacyl-CoA synthase of the disclosure.
In one aspect the disclosure provides for a genetically modified organism expressing a selected 3-ketoacyl-CoA synthase of the disclosure.
In one aspect, the disclosure provides for a method of producing a genetically modified organism that expresses a selected 3-ketoacyl-CoA synthase of the disclosure, comprising transforming a microorganism with a polynucleotide of the disclosure.
In one aspect the disclosure provides for a genetically modified organism capable of producing a fatty acid or fatty acid-derived product having a carbon chain length of C6 or greater at a rate or titer above a control organism lacking the genetic modification, wherein the genetically modified organism does not comprise any one of SEQ ID NO:121, SEQ ID NO:122, and SEQ ID NO:123. In some embodiments, a genetically modified organism comprises a vector or plasmid of the disclosure. In some embodiments, the genetically modified organism is transformed with a vector or plasmid. In some embodiments, the genetically modified organism comprises a polynucleotide of the disclosure. In some embodiments, the genetically modified organism, expresses a modified polypeptide and/or polynucleotide of the disclosure. In some embodiments, the genetically modified organism, expresses an NphT7 homolog or a modified NphT7 polypeptide of the disclosure. In some embodiments, the genetically modified organism comprises a heterologous polypeptide capable of condensing a malonyl-CoA with an acyl-CoA having a carbon chain length greater than C2 to produce a 3-ketoacyl-CoA having a carbon chain length greater than C4. In some embodiments, the acyl-CoA is acetyl-CoA and the 3-ketoacyl-CoA is 3-ketobutyryl-CoA. In some embodiments, the acyl-CoA is acetyl-CoA and the 3-ketoacyl-CoA is 3-ketobutyryl-CoA. In some embodiments, the acyl-CoA is propionyl-CoA and the 3-ketoacyl-CoA is 3-ketovaleryl-CoA. In some embodiments, the genetically modified organism is capable of producing a free fatty acid or fatty acid-derived product with a carbon chain length C6, C8, C10, C12, C14, C16, C18, C20, or greater with >20, 30, 40, 50, 60, 70, 80, or 90% purity. In some embodiments, the genetically modified organism is capable of producing a free fatty acid or fatty acid-derived product at a rate of about 0.1 g/gDCW*hr, about 0.2 g/gDCW*hr, or greater. In some embodiments, the genetically modified organism further comprises an additional genetic modification that increases production rate of acyl-CoA. In some embodiments, the genetically modified organism, further comprises an additional genetic modification that increases production rate of malonyl-CoA. In some embodiments, the genetically modified organism, further comprise an additional genetic modification that inhibits a malonyl-ACP fatty acid synthesis pathway. In some embodiments, the genetically modified organism, further comprises an additional genetic modification reduces the conversion of malonyl-CoA to malonyl ACP. In some embodiments, the genetically modified organism, further comprises an additional genetic modification reduces the rate of condensation of malonyl-ACP with acetyl-ACP. In some embodiments, the genetically modified organism, further comprises one or more additional genetic modifications that fully or partially inhibit one or more reactions selected from the group consisting of glucose to methylglyoxal conversion, pyruvate to lactate conversion, acetyl-CoA to acetate conversion, acetyl-CoA to ethanol conversion, fatty acyl to acetyl-CoA conversion, and any combination thereof. In some embodiments, the genetically modified organism, comprises a polynucleotide encoding a 3-ketoacyl-CoA synthase that comprises an amino acid sequence of at least 70% but less than 100% or about 100% homology to any one of SEQ ID NOs. 1-120. In some embodiments, the genetically modified organism, comprises one or more heterologous polypeptides selected from the group consisting of keto-CoA reductase (KCR), 3-hydroxy-acyl-CoA dehydratase (3HDh), enoyl CoA reductase (EnCR), thioesterase enzymes, and any combination thereof. In some embodiments, the genetically modified organism, comprises one or more heterologous KCR selected from the group consisting of fadB, fabG, fadJ, ech2, PhaB, PaFabG, and any combination thereof. In some embodiments, the genetically modified organism, comprises one or more heterologous 3HDh selected from the group consisting of fadB, fadJ, ech, ech2, crt, and any combination thereof. In some embodiments, the genetically modified organism, comprises one or more heterologous EnCR selected from the group consisting of ter, ccr, fadE, ydiO and any combination thereof. In some embodiments, the genetically modified organism, comprises one or more heterologous thioesterases selected from the group consisting of yciA, PA2801TE, ATTE, YbgC, tesA, YbfF, fadM, LpTE, CpTE (or CperfTE), and any combination thereof. In some embodiments, the genetically modified organism, comprises one or more heterologous 3-ketoacyl-CoA synthases selected from the group consisting of WT NphT7, NphT7 mutated at I147T, and NphT7 mutated at I147T and F217V, and any combination thereof, and at least one of: a heterologous fadB; a heterologous ter; and/or one or more thioesterases selected from the group consisting of tesA, yciA, PA2801TE, and any combination thereof. In some embodiments, the genetically modified organism, comprises one or more heterologous 3-ketoacyl-CoA synthases selected from the group consisting of WT NphT7, NphT7 mutated at I147T, NphT7 mutated at I147T and F217V, synthase III, and any combination thereof; and at least one of: one or more heterologous KCR selected from the group consisting of fadB and fabG; one or more heterologous 3HDh selected from the group consisting of fadB, ech and ech2; a heterologous ter; and/or one or more thioesterases selected from the group consisting of tesA, yciA, PA2801TE, and any combination thereof. In some embodiments, the genetically modified organism, comprises one or more heterologous 3-ketoacyl-CoA synthases selected from the group consisting of WT NphT7, NphT7 mutated at I147T, NphT7 mutated at I147T and F217V, synthase III, synthase IV, synthase V, and any combination thereof; and at least one of: one or more heterologous KCR selected from the group consisting of fadB and fabG; one or more heterologous 3HDh selected from the group consisting of fadB, ech and ech2; a heterologous ter; and/or one or more thioesterases selected from the group consisting of tesA, ATTE, YbgC, and any combination thereof. In some embodiments, the genetically modified organism, comprises one or more heterologous 3-ketoacyl-CoA synthases selected from the group consisting of WT NphT7, NphT7 mutated at I147T, NphT7 mutated at I147T and F217V, synthase III, synthase IV, synthase V, synthase VI, and any combination thereof; and at least one of: one or more heterologous KCR selected from the group consisting of fadB, fabG, fadJ, and any combination thereof; one or more heterologous 3HDh selected from the group consisting of fadB, fadJ, ech, and any combination thereof; a heterologous ter; and/or one or more thioesterases selected from the group consisting of tesA, ybgC, ybFF, and any combination thereof. In some embodiments, the genetically modified organism, comprises one or more heterologous 3-ketoacyl-CoA synthases selected from the group consisting of WT NphT7, NphT7 mutated at I147T, NphT7 mutated at I147T and F217V, synthase III, synthase IV, synthase V, synthase VI, and any combination thereof; and at least one of: one or more heterologous KCR selected from the group consisting of fadB and fadJ; one or more heterologous 3HDh selected from the group consisting of fadB and fadJ; one or more heterologous EnCR selected from the group consisting of ter, ydiO and fadE; and/or one or more thioesterases selected from the group consisting of tesA, fadM and any combination thereof. In some embodiments, the genetically modified organism, further comprises an additional genetic modification that reduces activity of one or more endogenous polypeptides selected from the group consisting of KCR, hbd, enoyl CoA reductase, thioesterase, and any combination thereof. In some embodiments, the genetically modified organism, further comprises an additional genetic modification that reduces activity of a temperature sensitive version of one or more endogenous polypeptides. In some embodiments, the genetically modified organism, comprises one or more vectors encoding a second genetic modification of the disclosure. In some embodiments, the genetically modified organism, comprises a heterologous transporter that can transport past a cell membrane a free fatty acid having a carbon chain length of C6 or greater. In some embodiments, the genetically modified organism, comprises a heterologous transporter that is an ABC transporter. In some embodiments, the genetically modified organism, comprises a fatty acid-derived product that is a fatty alcohol, a fatty aldehyde, a fatty alkene, a fatty amide, a fatty ester, a fatty alkane, or fatty diacid. In some embodiments, one or more of thioesterases are fully or partially knocked out, the thioesterases being selected from the group consisting of tesB, YciA, AtTE, CpTE, and any combination thereof. In some embodiments, the genetically modified organism is isolated and purified.
In one aspect the disclosure provides for a genetically modified organism having a genetic modification selected from the group consisting of F-, Δ(araD-araB)567, ΔlacZ4787(::rnB-3), LAM-, rph-1, Δ(rhaD-rhaB)568, hsdR514, ΔldhA::frt, ΔpflB::frt, ΔmgsA::frt, ΔpoxB::frt, Δpta-ack::frt, fabI(ts)-(S241F)-zeoR, Δtig::frt, ΔatoDAEB::frt, and ΔfadD::frt, and an additional genetic modification that increases synthesis of fatty acid from CoA substrates. In some embodiments, the genetically modified organism, comprises a deletion of a host gene, wherein the deletion results in increased malonyl-CoA production. In some embodiments, the genetically modified organism, comprises a deletion of one or more genes selected from the group consisting of lactate dehydrogenase, pyruvate formate lyase, methylglyoxal synthase, pyruvate oxidase, phosphotransacetylase acetate kinase, bifunctional acetyl-CoA reductase/alcohol dehydrogenase, and any combination thereof. In some embodiments, the genetically modified organism of the disclosure, further comprises an additional genetic modification that is associated with one or more enzymes selected from the group consisting of ACP, fabI, fabB, fabH, fabD, fabF, fabG, fabA, fabZ, fabR, and any combination thereof. In some embodiments, he genetically modified organism of the disclosure, further comprises an additional genetic modification that is associated with one or more enzymes selected from the group consisting of udhA, pntAB, PDH, CoAA, panD, aceA, aceB, aceK, GAPDH, pyk, pyk, gltA, CS, bicA, GOGAT, gdh, can, cynT, cynS, puuC, aldA, aldB, yieP, yibD, pstS, BAAT, rhtA, mdtM, yddG, yebS, yeeO, dedA, ycaP, ytfL, ybbP, yegH, ykgH, ytfF, eamB, ydhP, ypjD, mdlB, acrD, ydcO, emrD, citT, citS, citM, citH, and any combination thereof. In some embodiments, the genetically modified organism of the disclosure, further comprises an additional genetic modification associated with an ACCase enzyme. In some embodiments, the genetically modified organism of the disclosure, further comprises an additional genetic modification that is associated with one or more enzymes selected from the group consisting of cscA, cscB, cscK, galP, galKf, and any combination thereof. In some embodiments, the genetically modified organism, further comprises an additional genetic modification that is associated with one or more enzymes selected from the group consisting of fadE, fadD, fadA, fadB, fadI, fadJ, ydiO, paaJ, yqeF, tig, atoD, atoA, atoE, atoB, and any combination thereof. In some embodiments, the genetically modified organism, further comprises an additional genetic modification that is associated with one or more enzymes selected from the group consisting of NphT7, SaFabH, BsFabH, PaFabH, MtFabH, FabH, PaFabG, fabG, hbd, crt, ech, ech2, ter, ccr, and any combination thereof. In some embodiments, the genetically modified organism, further comprises an additional genetic modification resulting in expression of a heterologous thioesterase. In some embodiments, the genetically modified organism any claim, comprises one or more heterologous thioesterases selected from the group consisting of tesA, ‘tesA, tesB, yciA, ybgC, ybfF, fadM, AtTE, CpTE (or CperfTE), LpTE, Pa2801TE, and any combination thereof. In some embodiments, the genetically modified organism, further comprises an additional genetic modification resulting in expression of a heterologous wax ester synthase. In some embodiments, the genetically modified organism, comprises one or more heterologous wax ester synthases selected from the group consisting of Maq1, Pcry1, Rjos1, Abork1, and any combination thereof. In some embodiments, the genetically modified organism, further comprises an additional genetic modification that results in expression of one or more heterologous proteins selected from the group consisting of prpE, phaA, phaB, phaC, THNS, THNS″, and any combination thereof. In some embodiments, the genetically modified organism is a microorganism. In some embodiments, the genetically modified organism is E. Coli.
In one aspect the disclosure provides for a method of producing from malonyl-CoA a free fatty acid that has a carbon chain length of C6 or greater comprising culturing a transformed microorganism with a carbon feed source, thereby producing the free fatty acid.
In one aspect the disclosure provides for a method of producing from malonyl-CoA a free fatty acid that has a carbon chain length of C6 or greater comprising: inducing expression of a polypeptide in a microorganism; and culturing a transformed microorganism with a carbon feed source, thereby producing the free fatty acid.
In one aspect the disclosure provides for a method of producing from malonyl-CoA a free fatty acid that has a carbon chain length of C6 or greater comprising: providing a genetically modified microorganism; and culturing a transformed microorganism with a carbon feed source, thereby producing the free fatty acid.
In one aspect the disclosure provides for a method of producing a free fatty acid that has a carbon chain length of C6 or greater comprising culturing a microorganism under conditions sufficient to increase acyl-CoA and malonyl-CoA production.
In one aspect the disclosure provides for a method of producing a free fatty acid that has a carbon chain length of C6 or greater, comprising culturing a microorganism under conditions sufficient to enable condensation of a malonyl-CoA and an acyl-CoA of a carbon chain length of C2 or greater, whereby the condensation results in production of a keto-acyl CoA product having a chain length of C6 or greater.
In one aspect the disclosure provides for a method of producing a free fatty acid that has a carbon chain length of C6 or greater, comprising culturing a microorganism under conditions sufficient to reduce a keto group in a keto-acyl CoA product having a carbon chain length of C6 or greater, hereby producing a hydroxyl-acyl-CoA product having a carbon chain length of C6 or greater.
In one aspect, the disclosure provides for a method of producing a free fatty acid that has a carbon chain length of C6 or greater, comprising culturing a microorganism under conditions sufficient to perform a dehydratase reaction of a hydroxyl-acyl-CoA producing having a carbon chain length of C6 or greater to produce an enoyl-acyl-CoA product having a carbon chain length of C6 or greater.
In one aspect, the disclosure provides a method of producing a free fatty acid that has a carbon chain length of C6 or greater, comprising culturing a microorganism under conditions sufficient to reduce an enoyl group of an enoyl-acyl-CoA product having a carbon chain length of C6 or greater to produce an acyl-CoA product having a carbon chain length of C6 or greater.
In one aspect the disclosure provides a method for a method of producing a free fatty acid that has a carbon chain length of C6 or greater, comprising culturing a microorganism under conditions sufficient to remove a CoA group from an acyl-CoA product having a carbon chain length of C6 or greater to produce a free fatty acid or fatty acid-derived product having a carbon chain length of C6 or greater.
In one aspect the disclosure provides for a method of producing a free fatty acid or fatty acid-derived product of chain length of C6 or greater from malonyl-CoA, comprising: culturing a genetically modified organism under conditions sufficient to increase acyl CoA and malonyl-CoA production, condensing the acyl CoA and malonyl-CoA in the genetically modified organism to produce a keto-acyl CoA product having a carbon chain length of C6 or greater; reducing a keto-group in the keto-acyl CoA product to product a hydroxyl-acyl-CoA product having a carbon chain length of C6 or greater; performing a dehydratase reaction on the hydroxyl-acyl-CoA product to produce an enoyl-acyl-CoA product having a carbon chain length of C6 or greater; and reducing an enoyl group of the enoyl-acyl-CoA product to produce an acyl-CoA product having a carbon chain length of C6 or greater; and removing a CoA group from the acyl-CoA product to produce the free fatty acid or fatty acid-derived product having a carbon chain length of C6 or greater. In some embodiments, at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of free fatty acids produced by a genetically modified organism comprise a carbon chain length of C6 or greater. In some embodiments, the method comprises culturing a genetically modified organism that comprises one or more heterologous 3-ketoacyl-CoA synthases selected from the group consisting of WT NphT7, NphT7 mutated at I147T, NphT7 mutated at I147T and F217V, and any combination thereof; and at least one of: a heterologous fadB; a heterologous ter; and/or one or more thioesterases selected from the group consisting of yciA and PA2801TE. In some embodiments, at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of free fatty acids produced by a genetically modified organism comprise a carbon chain length of C8 or greater. In some embodiments, the method further comprises culturing a genetically modified organism that comprises one or more heterologous 3-ketoacyl-CoA synthases selected from the group consisting of WT NphT7, NphT7 mutated at I147T, NphT7 mutated at I147T and F217V, synthase III, and any combination thereof; and at least one of: one or more heterologous KCR selected from the group consisting of fadB and fabG; one or more heterologous 3HDh selected from the group consisting of fadB, ech and ech2; a heterologous ter; and/or one or more thioesterases selected from the group consisting of tesA, yciA, PA2801TE, and any combination thereof. In some embodiments, at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of free fatty acids produced by a genetically modified organism comprise a carbon chain length of C10 or greater. In some embodiments, the method further comprises culturing a genetically modified organism that comprises one or more heterologous 3-ketoacyl-CoA synthases selected from the group consisting of WT NphT7, NphT7 mutated at I147T, NphT7 mutated at I147T and F217V, synthase III, synthase IV, synthase V, and any combination thereof; at least one of: one or more heterologous KCR selected from the group consisting of fadB and fabG; one or more heterologous 3HDh selected from the group consisting of fadB, ech and ech2; a heterologous ter; and/or one or more thioesterases selected from the group consisting of tesA, ATTE, YbgC, and any combination thereof. In some embodiments, at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of free fatty acids produced by a genetically modified organism comprise a carbon chain length of C12. In some embodiments, the method further comprises culturing a genetically modified organism that comprises one or more heterologous 3-ketoacyl-CoA synthases selected from the group consisting of WT NphT7, NphT7 mutated at I147T, NphT7 mutated at I147T and F217V, synthase III, synthase IV, synthase V, synthase VI, and any combination thereof; and at least one of: one or more heterologous KCR selected from the group consisting of fadB, fabG, fadJ, and any combination thereof; one or more heterologous 3HDh selected from the group consisting of fadB, fadJ, ech, and any combination thereof; a heterologous ter; and/or one or more thioesterases selected from the group consisting of tesA, ybgC, ybFF, and any combination thereof. In some embodiments, at least 50%, 60%, 70%, 80%, or 90% of free fatty acids produced by a genetically modified organism comprise a carbon chain length of C14 or C16. In some embodiments, the method further comprises culturing a genetically modified organism that comprises one or more heterologous 3-ketoacyl-CoA synthases selected from the group consisting of WT NphT7, NphT7 mutated at I147T, NphT7 mutated at I147T and F217V, synthase III, synthase IV, synthase V, synthase VI, and any combination thereof; and at least one of: one or more heterologous KCR selected from the group consisting of fadB and fadJ; one or more heterologous 3HDh selected from the group consisting of fadB and fadJ; one or more heterologous EnCR selected from the group consisting of ter, ydiO and fadE; and/or one or more thioesterases selected from the group consisting of tesA, fadM, and any combination thereof. In some embodiments, the method further comprises a cycle that comprises reactions, wherein the cycle comprises reactions employing: a NphT7, a KCR, a 3HDh, and an EnCR, wherein at least one, two, three, four, five, six, seven, eight, or nine cycles are conducted, and at least one of the NphT7, KCR, 3HDh, and/or EnCR is modified.
In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product produced from a genetically modified organism.
In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product produced by a method of the disclosure. In some embodiments, the fatty acid-derived product is a fatty alcohol, fatty amide, fatty ester, fatty aldehyde, fatty alkene, fatty alkane, or fatty diacid, each of which is substituted or unsubstituted.
In one aspect the disclosure provides for use of a genetically modified organism for producing a fatty acid having a carbon chain length of C6 or greater.
In one aspect the disclosure provides for a system for producing a free fatty acid or fatty acid-derived product comprising a carbon chain length of C6 or greater comprising: one or more genetically modified organisms and/or modified polypeptides; and an incubator configured for culturing the one or more genetically modified organisms. In some embodiments, the system comprises a culture medium that comprises a carbon feed source. In some embodiments, the system comprises a purification system for purifying a free fatty acid or fatty acid-derived product. In some embodiments, the system comprises at least two strains of genetically modified organisms. In some embodiments, the system comprises at least three strains of genetically modified organisms. In some embodiments, the system is capable of producing a free fatty acid or fatty acid-derived product at a titer of about 5 g/L, about 10 g/L, or greater. In some embodiments, the system is capable of producing a free fatty acid or fatty acid-derived product comprising a carbon chain of C6 or greater at a concentration of about 0.5 g/L or greater. In some embodiments, the system is capable of producing a free fatty acid or fatty acid-derived product comprising a C12 carbon chain at a concentration of about 0.7 g/L or greater. In some embodiments, the system is capable of producing a free fatty acid or fatty acid-derived product comprising a C14 carbon chain at a concentration of about 0.7 g/L or greater. In some embodiments, the system is capable of producing a free fatty acid or fatty acid-derived product comprising a C16 carbon chain at a concentration of about 0.8 g/L or greater. In some embodiments, the system is capable of yielding a free fatty acid or fatty acid-derived product at about 0.125 g/g, about 0.16 g/g, or greater. In some embodiments, the system further comprises a mixing apparatus. In some embodiments, the system further comprises a heating apparatus, wherein the incubator comprises the heating apparatus. In some embodiments, the system further comprises a reservoir. In some embodiments, the system further comprises a pump. In some embodiments, the system the reservoir is operably connected to the incubator, and wherein the pump is operably configured to pump material from the reservoir to the incubator. In some embodiments, the system further comprises a lysing apparatus. In some embodiments, the system further comprises an extracting apparatus. In some embodiments, the system further comprises a distillation apparatus.
In one aspect the disclosure provides for a genetically modified organism that is Clostridium, Zymomonas, Escherichia, Salmonella, Rhodococcus, Pseudomonas, Streptomyces, Bacillus, Lactobacillus, Enterococcus, Alcaligenes, Klebsiella, Paenibacillus, Arthrobacter, Corynebacterium, Brevibacterium, Pichia, Candida, Hansenula, Thraustochytrids, Bacteriophage, or Saccharomyces. In some embodiments, the genetically modified organism is a prokaryotic cell. In some embodiments, the genetically modified organism is a eukaryotic cell. In some embodiments, the genetically modified organism is a yeast cell. In some embodiments, the genetically modified organism is a bacteria cell. In some embodiments, the genetically modified organism is a fungi cell. In some embodiments, the genetically modified organism is a microalgae cell. In some embodiments, the genetically modified organism is an algae cell.
In one aspect the disclosure provides for a carbon source comprising a C6 carbon source. In some embodiments, the carbon source comprises a C3 carbon source. In some embodiments, the carbon source comprises one or more cellulosic sugars. In some embodiments, the carbon source comprises glucose, sucrose, fructose, dextrose, lactose, xylose, or any combination thereof. In some embodiments, the carbon source comprises less than about 50%, 40%, 30%, 20%, 10%, or 5% by mass of glycerol.
In one aspect the disclosure provides for a biomass comprising a genetically modified organism. In some embodiments, the biomass comprises a lysed genetically modified organism. In some embodiments, the biomass comprises a modified NphT7 polypeptide. In some embodiments, the biomass comprises a modified polypeptide. In some embodiments, the biomass comprises a polynucleotide. In some embodiments, the biomass comprises a free fatty acid or fatty acid-derived product. In some embodiments, the biomass is dehydrated.
In one aspect the disclosure provides for a broth comprising a genetically modified organism. In one aspect the disclosure provides for a broth comprising a lysed genetically modified organism. In one aspect the disclosure provides for a broth comprising a modified NphT7 polypeptide. In one aspect the disclosure provides for a broth comprising a modified polypeptide. In one aspect the disclosure provides for a broth comprising a polynucleotide of the disclosure. In one aspect the disclosure provides for a broth comprising a free fatty acid or fatty acid-derived product of the disclosure.
In one aspect the disclosure provides for an acyl-CoA product, comprising about 15% to 50% by mass of acyl-CoA having a carbon chain length of C4. In one aspect the disclosure provides for an acyl-CoA product, comprising about 40% to 50% by mass of acyl-CoA having a carbon chain length of C6. In one aspect the disclosure provides for an acyl-CoA product, comprising about 5% to 30% by mass of acyl-CoA having a carbon chain length of C8. In one aspect the disclosure provides for an acyl-CoA product, comprising about 1% to 20% by mass of acyl-CoA having a carbon chain length of C12. In one aspect the disclosure provides for an acyl-CoA product, wherein the mass ratio of acyl-CoA having a carbon chain length of C4, acyl-CoA having a carbon chain length of C6, acyl-CoA having a carbon chain length of C8, and acyl-CoA having a carbon chain length of C12, is about 2:4:2:1. In one aspect the disclosure provides for an acyl-CoA product, wherein the mass ratio of acyl-CoA having a carbon chain length of C4, acyl-CoA having a carbon chain length of C6, and acyl-CoA having a carbon chain length of C8, is about 7:8:1. In one aspect the disclosure provides for an acyl-CoA product, wherein the mass ratio of acyl-CoA having a carbon chain length of C4, acyl-CoA having a carbon chain length of C6, acyl-CoA having a carbon chain length of C8, and acyl-CoA having a carbon chain length of C12, is about 2:1:1:1. In one aspect the disclosure provides for an acyl-CoA product, wherein the mass ratio of acyl-CoA having a carbon chain length of C4, acyl-CoA having a carbon chain length of C6, acyl-CoA having a carbon chain length of C8, and acyl-CoA having a carbon chain length of C12, is about 8:2:3:1. In some embodiments, the acyl-CoA product is selected from the group consisting of 3-ketoacyl-CoA, 3-hydroxyacyl-CoA, and enoyl-CoA.
In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, comprising about 15% to 50 by mass of a free fatty acid or fatty acid-derivative having a carbon chain length of C4. In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, comprising about 40% to 50% by mass of a free fatty acid or fatty acid-derivative having a carbon chain length of C6. In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, comprising about 5% to 30% by mass of a free fatty acid or fatty acid-derivative having a carbon chain length of C8. In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, comprising about 1% to 20% by mass of a free fatty acid or fatty acid-derivative having a carbon chain length of C12. In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, wherein the mass ratio of a free fatty acid or fatty acid-derivative having a carbon chain length of C4, a free fatty acid or fatty acid-derivative having a carbon chain length of C6, a free fatty acid or fatty acid-derivative having a carbon chain length of C8, and acyl-CoA having a carbon chain length of C12, is about 2:4:2:1. In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, wherein the mass ratio of a free fatty acid or fatty acid-derivative having a carbon chain length of C4, a free fatty acid or fatty acid-derivative having a carbon chain length of C6, and a free fatty acid or fatty acid-derivative having a carbon chain length of C8, is about 7:8:1. In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, wherein the mass ratio of a free fatty acid or fatty acid-derivative having a carbon chain length of C4, a free fatty acid or fatty acid-derivative having a carbon chain length of C6, a free fatty acid or fatty acid-derivative having a carbon chain length of C8, and a free fatty acid or fatty acid-derivative having a carbon chain length of C12, is about 2:1:1:1. In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, wherein the mass ratio of a free fatty acid or fatty acid-derivative having a carbon chain length of C4, a free fatty acid or fatty acid-derivative having a carbon chain length of C6, a free fatty acid or fatty acid-derivative having a carbon chain length of C8, and a free fatty acid or fatty acid-derivative having a carbon chain length of C12, is about 8:2:3:1. In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, comprising about 16% or greater mass of a free fatty acid or fatty acid-derivative having a carbon chain length of C14. In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, comprising about 20% or greater mass of a free fatty acid or fatty acid-derivative having a carbon chain length of C16. In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, comprising about 36% or greater mass of a free fatty acid or fatty acid-derivative having a carbon chain length of C14 or C16. In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, comprising about 60% or greater mass of a free fatty acid or fatty acid-derivative having a carbon chain length of C14 or C16. In one aspect the disclosure provides for a free fatty acid or fatty acid-derived product, wherein the mass ratio of a free fatty acid or fatty acid-derivative having a carbon chain length of C4, a free fatty acid or free fatty acid-derivative having a carbon chain length of C6, a free fatty acid or fatty acid-derivative having a carbon chain length of C8, a free fatty acid or fatty acid-derivative having a carbon chain length of C10, a free fatty acid or fatty acid-derivative having a carbon chain length of C12, a free fatty acid having a carbon chain length of C14, a free fatty acid or fatty acid-derivative having a carbon chain length of C16, and a free fatty acid or fatty acid-derivative having a carbon chain length of C18, is about 10:20:12:7:8:16:20:7, or about 1:2:1:1:1:2:2:1. In one aspect the disclosure provides for an acyl-CoA product, free fatty acid product, or fatty acid-derived product, that is isolated and purified.
In one aspect the disclosure provides for a method of making one or more fatty acid-derived products selected from the group consisting of fatty ester, fatty amide, fatty alcohol, fatty aldehyde, fatty alkene, fatty alkane, fatty diacid, and any combination thereof, comprising: contacting a carbon source with a microorganism to form a free fatty acid having a carbon chain length of C6 or greater; and converting the free fatty acid to the fatty acid-derived product, wherein the fatty acid-derived product comprises a carbon chain length of C6 or greater. In one aspect the disclosure provides for a method of making an ester of a fatty acid, comprising esterifying a fatty acid produced by a genetically modified organism. In one aspect the disclosure provides for a method of making an amide of a fatty acid, comprising forming an amide of a fatty acid produced by a genetically modified organism of the disclosure. In one aspect the disclosure provides for a method of making a fatty alcohol, comprising forming the fatty alcohol from the fatty acid produced by a genetically modified organism of the disclosure. In one aspect the disclosure provides for a method of making an aldehyde of a fatty acid, comprising forming an aldehyde of a fatty acid produced by a genetically modified organism of the disclosure.
In one aspect the disclosure provides for a fuel comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for a lotion comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for a soap comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for a food comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for a cream comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for a shampoo comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for a conditioner comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for a cleaner comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for a detergent comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for a lubricant comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for a paint comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for a stain comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for an ink comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In one aspect the disclosure provides for a pharmaceutical formulation comprising the acyl-CoA product, free fatty acid product, or fatty-acid derived product of the disclosure. In some embodiments, the product further comprises one or more active agents. In some embodiments, the product further comprises an excipient.
In one aspect the disclosure provides for one or more isolated and purified polynucleotides comprising exogenous nucleic acid molecules encoding proteins comprising an acetoacetyl CoA synthase, a keto-CoA reductase, a 3-hydroxy-acyl-CoA dehydratase, an enoyl-CoA reductase, and a thioesterase, wherein the 3-ketoacyl-CoA synthase is selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, synthase III, synthase IV, synthase V, and synthase VI; the keto-CoA reductase is selected from the group consisting of hbd, fadB, fabG and fadJ the 3-hydroxy-acyl-CoA dehydratase is selected from the group consisting of crt, ech, fadB, and fadJ; the enoyl-CoA reductase is selected from the group consisting of ter, ydiO and fadE; and the thioesterase is selected from the group consisting of AtTE, CpTE (or CperfTE), fadM, LpTE, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA. In some embodiments, the 3-ketoacyl-CoA synthase is NphT7; the keto-CoA reductase is selected from the group consisting of hbd and fadB; the 3-hydroxy-acyl-CoA dehydratase is selected from the group consisting of crt and fadB; the enoyl-CoA reductase is ter; and the thioesterase is yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a four carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of tesB and yciA. In some embodiments, the 3-ketoacyl-CoA synthase is NphT7 and wherein the proteins encoded by the polynucleotides are capable of producing a four carbon fatty acid or fatty acid derived product. In some embodiments, the keto-CoA reductase is selected from the group consisting of hbd and fadB, and wherein the proteins encoded by the polynucleotides are capable of producing a four carbon fatty acid or fatty acid derived product. In some embodiments, the 3-hydroxy-acyl-CoA dehydratase is selected from the group consisting of crt and fadB, and wherein the proteins encoded by the polynucleotides are capable of producing a four carbon fatty acid or fatty acid derived product. In some embodiments, the enoyl-CoA reductase is ter, and wherein the proteins encoded by the polynucleotides are capable of producing a four carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of CpTE, fadM, PA2801TE, tesB, ybgC, ybfF, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a four carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of tesB and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a four carbon fatty acid or fatty acid derived product. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, and NphT7 I147T, F217V; the keto-CoA reductase is fadB; the 3-hydroxy-acyl-CoA dehydratase is fadB; the enoyl-CoA reductase is ter; and the thioesterase is selected from the group consisting of AtTE, CpTE (or CperfTE), PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a six carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of PA2801TE, tesB, and yciA. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, and NphT7 I147T and F217V, and wherein the proteins encoded by the polynucleotides are capable of producing a six carbon fatty acid or fatty acid derived product. In some embodiments, the keto-CoA reductase is fadB, and wherein the proteins encoded by the polynucleotides are capable of producing a six carbon fatty acid or fatty acid derived product. In some embodiments, the 3-hydroxy-acyl-CoA dehydratase is fadB, and wherein the proteins encoded by the polynucleotides are capable of producing a six carbon fatty acid or fatty acid derived product. In some embodiments, the enoyl-CoA reductase is ter, and wherein the proteins encoded by the polynucleotides are capable of producing a six carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected form the group consisting of AtTE, CpTE (or CperfTE), PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a six carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected form the group consisting of PA2801TE, tesB, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a six carbon fatty acid or fatty acid derived product. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, and synthase III; the keto-CoA reductase is selected from the group consisting of fadB and fabG; the 3-hydroxy-acyl-CoA dehydratase is selected from the group consisting of fadB, ech and ech2; the enoyl-CoA reductase is ter; and the thioesterase is selected from the group consisting of AtTE, CpTE (or CperfTE), fadM, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA; and wherein the proteins encoded by the polynucleotides are capable of producing an eight carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of PA2801TE, tesB, and yciA. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, and synthase III, and wherein the proteins encoded by the polynucleotides are capable of producing an eight carbon fatty acid or fatty acid derived product. In some embodiments, the keto-CoA reductase is selected from the group consisting of fadB and fabG, and wherein the proteins encoded by the polynucleotides are capable of producing an eight carbon fatty acid or fatty acid derived product. In some embodiments, the 3-hydroxy-acyl-CoA dehydratase is selected form the group consisting of fadB, ech and ech2, and wherein the proteins encoded by the polynucleotides are capable of producing an eight carbon fatty acid or fatty acid derived product. In some embodiments, the enoyl-CoA reductase is ter, and wherein the proteins encoded by the polynucleotides are capable of producing an eight carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of AtTE, CpTE (or CperfTE), fadM, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing an eight carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of PA2801TE, tesB, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing an eight carbon fatty acid or fatty acid derived product. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, synthase III, synthase IV, and synthase V; the keto-CoA reductase is selected from the group consisting of fadB and fabG; the 3-hydroxy-acyl-CoA dehydratase is selected from the group consisting of fadB, ech and ech2; the enoyl-CoA reductase is ter; and the thioesterase is selected from the group consisting of AtTE, CpTE, fadM, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a ten carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of tesB and yciA. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, synthase III, synthase IV, and synthase V, and wherein the proteins encoded by the polynucleotides are capable of producing a ten carbon fatty acid or fatty acid derived product. In some embodiments, the keto-CoA reductase is selected from the group consisting of fadB and fabG, and wherein the proteins encoded by the polynucleotides are capable of producing a ten carbon fatty acid or fatty acid derived product. In some embodiments, the 3-hydroxy-acyl-CoA dehydratase is selected from the group consisting of fadB, ech and ech2, and wherein the proteins encoded by the polynucleotides are capable of producing a ten carbon fatty acid or fatty acid derived product. In some embodiments, the enoyl-CoA reductase is ter, and wherein the proteins encoded by the polynucleotides are capable of producing a ten carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of AtTE, CpTE, fadM, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a ten carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of tesB and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a ten carbon fatty acid or fatty acid derived product. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, synthase III, synthase IV, synthase V, and synthase VI; the keto-CoA reductase is selected from the group consisting of fadB, fabG, and fadJ, the 3-hydroxy-acyl-CoA dehydratase is selected from the group consisting of fadB, ech, and fadJ; the enoyl-CoA reductase is ter; and the thioesterase is selected from the group consisting of AtTE, CpTE (or CperfTE), fadM, LpTE, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a twelve carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of fadM, PA2801TE, tesA, tesB, and yciA. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, synthase III, synthase IV, synthase V, and synthase VI, and wherein the proteins encoded by the polynucleotides are capable of producing a twelve carbon fatty acid or fatty acid derived product. In some embodiments, the keto-CoA reductase is selected form the group consisting of fadB, fabG, and fadJ, and wherein the proteins encoded by the polynucleotides are capable of producing a twelve carbon fatty acid or fatty acid derived product. In some embodiments, the 3-hydroxy-acyl-CoA dehydratase is selected from the group consisting of fadB, ech, and fadJ, and wherein the proteins encoded by the polynucleotides are capable of producing a twelve carbon fatty acid or fatty acid derived product. In some embodiments, the enoyl-CoA reductase is ter, and wherein the proteins encoded by the polynucleotides are capable of producing a twelve carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of AtTE, CpTE (or CperfTE), fadM, LpTE, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a twelve carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of fadM, PA2801TE, tesA, tesB, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a twelve carbon fatty acid or fatty acid derived product. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, synthase III, synthase IV, synthase V, and synthase VI; the keto-CoA reductase is selected from the group consisting of fadB, and fadJ; the 3-hydroxy-acyl-CoA dehydratase is selected form the group consisting of fadB, and fadJ; the enoyl-CoA reductase is selected from the group consisting of ter, ydiO and fadE; and the thioesterase is selected from the group consisting of AtTE, CpTE (or CperfTE), fadM, LpTE, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a fatty acid with a carbon chain length of at least fourteen carbons. In some embodiments, the thioesterase is selected from the group consisting of fadM, tesA, tesB, and yciA, and the proteins encoded by the polynucleotides are capable of producing a fourteen carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of AtTE, CpTE (or CperfTE), fadM, Pa2801TE, tesA, tesB, ybfF, ybgC, and yciA, and the proteins encoded by the polynucleotides are capable of producing a sixteen carbon fatty acid or fatty acid derived product. In some embodiments, the thioesterase is selected from the group consisting of AtTE, fadM, tesA, tesB, ybfF, ybgC, and yciA, and the proteins encoded by the polynucleotides are capable of producing a sixteen carbon fatty acid or fatty acid derived product. In some embodiments, one or more 3-ketoacyl-CoA synthases are selected from the group consisting of NphT7, NphT7 I147T, NphT7 F217V, NphT7 I147T and F217V, Npth7 I147S, Npth7 I147S and F217V, synthase III, synthase IV, synthase V, and synthase VI, and wherein the proteins encoded by the polynucleotides are capable of producing a fatty acid with a carbon chain length of greater than or equal to fourteen carbons. In some embodiments, the keto-CoA reductase is selected form the group consisting of fadB, and fadJ, and wherein the proteins encoded by the polynucleotides are capable of producing a fatty acid with a carbon chain length of greater than or equal to fourteen carbons. In some embodiments, the 3-hydroxy-acyl-CoA dehydratase is selected form the group consisting of fadB, and fadJ, and wherein the proteins encoded by the polynucleotides are capable of producing a fatty acid with a carbon chain length of greater than or equal to fourteen carbons. In some embodiments, the enoyl-CoA reductase is selected form the group consisting of ter, ydiO and fadE, and wherein the proteins encoded by the polynucleotides are capable of producing a fatty acid with a carbon chain length of greater than or equal to fourteen carbons. In some embodiments, the thioesterase is selected form the group consisting of AtTE, CpTE (or CperfTE), fadM, LpTE, PA2801TE, tesA, tesB, ybfF, ybgC, and yciA, and wherein the proteins encoded by the polynucleotides are capable of producing a fatty acid with a carbon chain length of greater than or equal to fourteen carbons.
In one aspect the disclosure provides for one or more isolated and purified polynucleotides comprising exogenous nucleic acid molecules encoding proteins comprising a 3-oxoacyl-(acyl carrier protein) synthase III from a species selected from the group consisting of Alishewanella aestuarii B11, Arcobacter butzleri ED-1, Clostridiales bacterium 1_7_47 FAA, Gluconacetobacter oboediens 174Bp2, Gordonia aichiensis NBRC 108223, Mesorhizobium sp. STM 4661, Pelosinus fermentans DSM 17108, Phaeobacter gallaeciensis 2.10, Ralstonia solanacearum Po82, Saccharomonospora azurea NA-128, Saccharomonospora glauca K62, and Verrucosispora maris AB-18-032, wherein the proteins encoded by the polynucleotides are capable of producing a fatty acid. In some embodiments, the 3-oxoacyl-(acyl carrier protein) synthase III is from a species selected from the group consisting of Pelosinus fermentans DSM 17108, Saccharomonospora glauca K62, Verrucosispora maris AB-18-032, and Clostridiales bacterium 1_7_47 FAA, and wherein the proteins encoded by the polynucleotides are capable of producing an acetyl-CoA. In some embodiments, the 3-oxoacyl-(acyl carrier protein) synthase III is from a species selected from the group consisting of Saccharomonospora glauca K62, Saccharomonospora azurea NA-128, Mesorhizobium sp. STM 4661, and Clostridiales bacterium 1_7_47 FAA, and wherein the proteins encoded by the polynucleotides are capable of producing a four carbon fatty acid or fatty acid derived product. In some embodiments, the 3-oxoacyl-(acyl carrier protein) synthase III is from a species selected from the group consisting of Gordonia aichiensis NBRC 108223, Arcobacter butzleri ED-1, Clostridiales bacterium 1_7_47 FAA, Saccharomonospora glauca K62, and Ralstonia solanacearum Po82, and wherein the proteins encoded by the polynucleotides are capable of producing a six carbon fatty acid or fatty acid derived product. In some embodiments, the 3-oxoacyl-(acyl carrier protein) synthase III is from a species selected from the group consisting of Gordonia aichiensis NBRC 108223, Gluconacetobacter oboediens 174Bp2, Arcobacter butzleri ED-1, Ralstonia solanacearum Po82, and Phaeobacter gallaeciensis 2.10, and wherein the proteins encoded by the polynucleotides are capable of producing an eight carbon fatty acid or fatty acid derived product. In some embodiments, the 3-oxoacyl-(acyl carrier protein) synthase III is from Alishewanella aestuarii B11, and wherein the proteins encoded by the polynucleotides are capable of producing a ten carbon fatty acid or fatty acid derived product. In some embodiments, the proteins encoded by the polynucleotides further comprise a 3-ketoacyl-CoA synthase from Streptomyces sp. (strain CL190).
All publications, patents, and patent applications herein are incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. In the event of a conflict between a term herein and a term in an incorporated reference, the term herein controls.
The details of one or more inventive embodiments are set forth in the accompanying drawings, the claims, and the description herein. Other features, objects, and advantages of the inventive embodiments disclosed and contemplated herein can be combined with any other embodiment unless explicitly excluded.
The present invention relates generally to various production methods and/or genetically modified microorganisms that have utility for fermentative production of various chemical products, to methods of making such chemical products that utilize populations of these microorganisms in vessels, and to systems for chemical production that employ these microorganisms and methods. Among the benefits of the present invention is increased specific productivity when such microorganisms produce a chemical product during a fermentation event or cycle.
The present invention provides production techniques and/or genetically modified microorganisms to produce a chemical product of interest, such as a fatty acid or fatty acid derived product. The invention provides for one or more means for modulating conversion of malonyl-CoA to fatty acyl molecules, wherein the production pathway comprises a malonyl-CoA dependent pathway that includes an enzymatic conversion step that uses malonyl-CoA as a substrate. In accordance with certain embodiments, the malonyl-CoA dependent pathway is also a malonyl-ACP independent pathway, and is used in combination with the inhibition of a microorganism's native malonyl-ACP dependent fatty acid synthase pathway. In accordance with certain other embodiments of the present invention, fatty acid or fatty acid derived products are produced in a manner dependent on both a malonyl-CoA dependent pathway and a malonyl-ACP dependent pathway.
The genetically modified microorganisms of the invention are metabolically engineered to increase utilization of malonyl-CoA for production of a fatty acid or fatty acid derived product, through a metabolic pathway that is at least in part malonyl-CoA dependent. The fatty acid derived products may include esters, aldehydes, alcohols, alkanes, alkenes, and diacids, with various degrees of desaturation and chain branching, and further downstream products made from such chemical products. Also, genetic modifications may be made to provide one or more chemical products.
The present invention also relates to genetically engineered microorganisms having encoded therein unique enzymes and combinations of enzymes that function within the malonyl-CoA dependent pathway to produce fatty acids or fatty acid derived products of specific chain lengths. The microorganisms and methods provide a cost-competitive means of producing relatively high concentrations of fatty acids or fatty acid derived products of specific chain lengths or products having a relatively narrow carbon chain length distribution (i.e., 2, 3, 4 or less than 5 different carbon chain lengths with in the fatty acid product, e.g. C8/C10 or C8/C10/C12).
As used herein unless otherwise indicated, open terms such as “contain,” “containing,” “include,” “including,” and the like mean comprising.
Some embodiments herein contemplate numerical ranges. When a numerical range is provided, the range includes the range endpoints. Numerical ranges include all values and subranges therein as if explicitly written out.
As used herein, the article “a” means one or more unless explicitly stated otherwise.
As used herein, herein unless otherwise indicated, the one letter abbreviations A, R, N, C, D, Q, E, G, H, I, L, K, M, F, P, S, T, W, Y and V, represent the twenty amino acids commonly found in peptides synthesized in nature.
As used herein, unless otherwise indicated, the convention Letter1NumberLetter2, when applied to polypeptides, means that the amino acid having the one letter code Letter 1, at Number position in the polypeptide, is substituted with the amino acid having the one letter code Letter2. For example, I147T means that the amino acid I, found at position 147 in the peptide, is substituted with the amino acid T.
As used herein, unless otherwise indicated, the symbol CNumber means a carbon backbone chain length having the indicated number of carbon atoms. For example, C20 means a chemical backbone having a 20 carbon chain length. Note that the number of carbons included in the carbon backbone does not include carbon contained in functional units attached to the backbone (e.g., a functional unit in a fatty acid derived product).
As used herein, “reduced enzymatic activity,” “reducing enzymatic activity,” “decreased enzymatic activity,” “decreasing enzymatic activity,” and the like is meant to indicate that a microorganism cell's, or an isolated enzyme, exhibits a lower level of activity than that measured in a comparable cell of the same species or its native enzyme. That is, enzymatic conversion of the indicated substrate(s) to indicated product(s) under known standard conditions for that enzyme is at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, or at least 90 percent less than the enzymatic activity for the same biochemical conversion by a native (non-modified) enzyme under a standard specified condition. These terms also can include elimination of that enzymatic activity. A decrease in enzymatic activity may be achieved in variety a ways known to those skilled in the art, including for example, a gene disruption or a gene deletion. A decrease in enzymatic activity may be temporal, be controlled through the expression of various genetic elements, or decrease in response to the cultivation conditions of the cell. A cell having reduced enzymatic activity of an enzyme can be identified using any method known in the art. For example, enzyme activity assays can be used to identify cells having reduced enzyme activity. See, for example, Enzyme Nomenclature, Academic Press, Inc., New York 2007.
As used herein, “increase enzymatic activity,” “increasing enzymatic activity,” and the like is meant to indicate that a microorganism cell's, or an isolated enzyme, exhibits a higher level of activity than that measured in a comparable cell of the same species or its native enzyme. That is, enzymatic conversion of the indicated substrate(s) to indicated product(s) under known standard conditions for that enzyme is at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, or at least 90 percent greater than the enzymatic activity for the same biochemical conversion by a native (non-modified) enzyme under a standard specified condition. These terms also can include addition of an exogenous enzymatic activity. An increase in enzymatic activity may be temporal, be controlled through the expression of various genetic elements, or increase in response to the cultivation conditions of the cell. A cell having increased enzymatic activity of an enzyme can be identified using any method known in the art, including the enzyme activity assays noted above used to identify cells having reduced enzyme activity.
As used herein, the term “gene disruption,” or grammatical equivalents thereof (and including “to disrupt enzymatic function,” “disruption of enzymatic function,” and the like), is intended to mean a genetic modification to a microorganism that renders the encoded gene product as having a reduced polypeptide activity compared with polypeptide activity in or from a microorganism cell not so modified. The genetic modification can be, for example, deletion of the entire gene, deletion or other modification of a regulatory sequence required for transcription or translation, deletion of a portion of the gene which results in a truncated gene product (e.g., enzyme) or by any of various mutation strategies that reduces activity (including to no detectable activity level) of the encoded gene product. A disruption may broadly include a deletion of all or part of the nucleic acid sequence encoding the enzyme, and also includes, but is not limited to other types of genetic modifications, e.g., introduction of stop codons, frame shift mutations, introduction or removal of portions of the gene, and introduction of a degradation signal, those genetic modifications affecting mRNA transcription levels and/or stability, and altering the promoter or repressor upstream of the gene encoding the enzyme.
In various contexts, a gene disruption is taken to mean any genetic modification to the DNA, mRNA encoded from the DNA, and the corresponding amino acid sequence that results in reduced polypeptide activity. Many different methods can be used to make a cell having reduced polypeptide activity. For example, a cell can be engineered to have a disrupted regulatory sequence or polypeptide-encoding sequence using common mutagenesis or knock-out technology. See, e.g., Methods in Yeast Genetics (1997 edition), Adams et al., Cold Spring Harbor Press (1998). One particularly useful method of gene disruption is complete gene deletion because it reduces or eliminates the occurrence of genetic reversions in the genetically modified microorganisms of the invention. Accordingly, a disruption of a gene whose product is an enzyme thereby disrupts enzymatic function. Alternatively, antisense technology can be used to reduce the activity of a particular polypeptide. For example, a cell can be engineered to contain a cDNA that encodes an antisense molecule that prevents a polypeptide from being translated. Further, gene silencing can be used to reduce the activity of a particular polypeptide.
The term “heterologous” is intended to include the term “exogenous” as the latter term is generally used in the art. Heterologous can refer to polypeptides and/or nucleic acids which are not ordinarily produced by the host cell. Such heterologous polypeptides and/or nucleic acid thus may comprise polypeptides which either do not have substantial amino acid sequence homology with those proteins produced by the host cell or may comprise polypeptides with substantial but incomplete homology to proteins produced by the host cell or the cell line from which the host cell is derived.
The term “heterologous DNA,” “heterologous nucleic acid sequence,” and the like as used herein refers to a nucleic acid sequence wherein at least one of the following is true: (a) the sequence of nucleic acids is foreign to (i.e., not naturally found in) a given host microorganism; (b) the sequence may be naturally found in a given host microorganism, but in an unnatural amount (e.g., greater than expected) or position; or (c) the sequence of nucleic acids comprises two or more subsequences that are not found in the same relationship to each other in nature. For example, regarding instance (c), a heterologous nucleic acid sequence that is recombinantly produced will have two or more sequences from unrelated genes arranged to make a new functional nucleic acid.
The term “antisense molecule” as used herein encompasses any nucleic acid molecule or nucleic acid analog (e.g., peptide nucleic acids) that contains a sequence that corresponds to the coding strand of an endogenous polypeptide. An antisense molecule also can have flanking sequences (e.g., regulatory sequences). Thus, antisense molecules can be ribozymes or antisense oligonucleotides.
As used herein, a ribozyme can have any general structure including, without limitation, hairpin, hammerhead, or axhead structures, provided the molecule cleaves RNA.
Bio-production, as used herein, may be aerobic, microaerobic, or anaerobic.
As used herein, the language “sufficiently homologous” refers to proteins or portions thereof that have amino acid sequences that include a minimum number of identical or equivalent amino acid residues when compared to an amino acid sequence of the amino acid sequences provided in this application (including the SEQ ID Nos./sequence listings) such that the protein or portion thereof is able to achieve the respective enzymatic reaction and/or other function. To determine whether a particular protein or portion thereof is sufficiently homologous may be determined by an assay of enzymatic activity, such as those commonly known in the art.
Descriptions and methods for sequence identity and homology are intended to be exemplary and it is recognized that these concepts are well-understood in the art. Further, it is appreciated that nucleic acid sequences may be varied and still encode an enzyme or other polypeptide exhibiting a desired functionality, and such variations are within the scope of the present invention.
Further to nucleic acid sequences, “hybridization” refers to the process in which two single-stranded polynucleotides bind non-covalently to form a stable double-stranded polynucleotide. The term “hybridization” may also refer to triple-stranded hybridization. The resulting (usually) double-stranded polynucleotide is a “hybrid” or “duplex.” “Hybridization conditions” will typically include salt concentrations of less than about 1M, more usually less than about 500 mM and less than about 200 mM. Hybridization temperatures can be as low as 5° C., but are typically greater than 22° C., more typically greater than about 30° C., and often are in excess of about 37° C. Hybridizations are usually performed under stringent conditions, i.e. conditions under which a probe will hybridize to its target subsequence. Stringent conditions are sequence-dependent and are different in different circumstances. Longer fragments may require higher hybridization temperatures for specific hybridization. As other factors may affect the stringency of hybridization, including base composition and length of the complementary strands, presence of organic solvents and extent of base mismatching, the combination of parameters is more important than the absolute measure of any one alone. Generally, stringent conditions are selected to be about 5° C. lower than the Tn, (temperature at which half the DNA is present in a single-stranded (denatured) form) for the specific sequence at a defined ionic strength and pH. Exemplary stringent conditions include salt concentration of at least 0.01 M to no more than 1 M Na ion concentration (or other salts) at a pH 7.0 to 8.3 and a temperature of at least 25° C. For example, conditions of 5×SSPE (750 mM NaCl, 50 mM Na Phosphate, 5 mM EDTA, pH 7.4) and a temperature of 25-30° C. are suitable for allele-specific probe hybridizations. For stringent conditions, see for example, Sambrook and Russell and Anderson “Nucleic Acid Hybridization” 1st Ed., BIOS Scientific Publishers Limited (1999), which is hereby incorporated by reference for hybridization protocols. “Hybridizing specifically to” or “specifically hybridizing to” or like expressions refer to the binding, duplexing, or hybridizing of a molecule substantially to or only to a particular nucleotide sequence or sequences under stringent conditions when that sequence is present in a complex mixture (e.g., total cellular) DNA or RNA.
The use of the phrase “segment of interest” is meant to include both a gene and any other nucleic acid sequence segment of interest. One example of a method used to obtain a segment of interest is to acquire a culture of a microorganism, where that microorganism's genome includes the gene or nucleic acid sequence segment of interest.
When the genetic modification of a gene product, i.e., an enzyme, is referred to herein, including the claims, it is understood that the genetic modification is of a nucleic acid sequence, such as or including the gene, that normally encodes the stated gene product, i.e., the enzyme.
In some embodiments a truncated respective polypeptide has at least about 90%, or at least about 91%, or at least about 92%, or at least about 93%, or at least about 94%, or at least about 95%, or at least about 96%, or at least about 97%, or at least about 98%, or at least about 99% of the full length of a polypeptide encoded by a nucleic acid sequence encoding the respective native enzyme, and more particularly at least 95% of the full length of a polypeptide encoded by a nucleic acid sequence encoding the respective native enzyme. By a polypeptide having an amino acid sequence at least, for example, 95% “identical” to a reference amino acid sequence of a polypeptide is intended that the amino acid sequence of the claimed polypeptide is identical to the reference sequence except that the claimed polypeptide sequence can include up to five amino acid alterations per each 100 amino acids of the reference amino acid of the polypeptide. In other words, to obtain a polypeptide having an amino acid sequence at least 95% identical to a reference amino acid sequence, up to 5% of the amino acid residues in the reference sequence can be deleted or substituted with another amino acid, or a number of amino acids up to 5% of the total amino acid residues in the reference sequence can be inserted into the reference sequence. These alterations of the reference sequence can occur at the amino or carboxy terminal positions of the reference amino acid sequence or anywhere between those terminal positions, interspersed either individually among residues in the reference sequence or in one or more contiguous groups within the reference sequence. In other embodiments truncation may be more substantial, as described elsewhere herein.
Species and other phylogenic identifications are according to the classification known to a person skilled in the art of microbiology.
Where methods and steps described herein indicate certain events occurring in certain order, those of ordinary skill in the art will recognize that the ordering of certain steps may be modified and that such modifications are in accordance with the variations of the invention. Additionally, certain steps may be performed concurrently in a parallel process when possible, as well as performed sequentially.
The meaning of abbreviations is as follows: “C” means Celsius or degrees Celsius, as is clear from its usage, DCW means dry cell weight, “s” means second(s), “min” means minute(s), “h,” “hr,” or “hrs” means hour(s), “psi” means pounds per square inch, “nm” means nanometers, “d” means day(s), “μL” or “uL” or “ul” means microliter(s), “mL” means milliliter(s), “L” means liter(s), “mm” means millimeter(s), “nm” means nanometers, “mM” means millimolar, “μM” or “uM” means micromolar, “M” means molar, “mmol” means millimole(s), “μmol” or “uMol” means micromole(s)”, “g” means gram(s), “μg” or “ug” means microgram(s) and “ng” means nanogram(s), “PCR” means polymerase chain reaction, “OD” means optical density, “OD600” means the optical density measured at a photon wavelength of 600 nm, “kDa” means kilodaltons, “g” means the gravitation constant, “bp” means base pair(s), “kbp” means kilobase pair(s), “% w/v” means weight/volume percent, “% v/v” means volume/volume percent, “IPTG” means isopropyl-g-D-thiogalactopyranoiside, “RBS” means ribosome binding site, “rpm” means revolutions per minute, “HPLC” means high performance liquid chromatography, “UPLC” means ultra performance liquid chromatography, and “GC” means gas chromatography.
By “means for modulating” is meant any one of the following: 1) providing in a microorganism cell at least one polynucleotide that encodes at least one polypeptide having certain enzymatic activity, wherein such enzymatic activity of the polypeptide so encoded is either: (a) exogenous, (b) native but is lower or higher than the enzymatic activity of its native form (such as by mutation and/or promoter substitution, etc.), or (c) modulated to have a reduced or increased enzymatic activity at any point during a fermentation process (such as by temperature sensitivity, inducible promoter, etc.); or 2) providing to a vessel comprising a microorganism cell or population an inhibitor that inhibits enzymatic activity or a supplement that increases enzymatic activity. These means may be provided in combination with one another.
As used herein, references to “synthase III”, “synthase IV”, “synthase V”, and “synthase VI” (except in the context of the name of a specific enzyme sequence included in a FASTA header in one of the Tables) shall refer to the third, fourth, fifth and sixth synthase, respectively, that is included in among a group of synthases. Synthase III, synthase IV, synthase V, and synthase VI may be any 3-ketoacyl-CoA synthase disclosed herein. For example, a reference herein to a genetically modified organism comprising a heterologous nucleic acid sequence encoding a 3-ketoacyl-CoA synthase selected from the group consisting of synthase III and synthase IV means either: (1) a genetically modified organism comprising a heterologous nucleic acid sequence encoding at least three 3-ketoacyl-CoA synthases wherein at least one of such 3-ketoacyl-CoA synthases is a 3-ketoacyl-CoA synthase disclosed herein; or (2) a genetically modified organism comprising a heterologous nucleic acid sequence encoding at least four 3-ketoacyl-CoA synthases wherein at least one of such 3-ketoacyl-CoA synthases is a 3-ketoacyl-CoA synthase disclosed herein.
The present invention relates to a fatty acid pathway that comprises four steps which utilizes a pathway that is similar to the type II fatty acid synthesis (FAS) system utilized by bacteria. Both fatty acid syntheses are shown below in Scheme 1. As illustrated in
The novel CoA dependent fatty acid pathway and the key enzymes associated therewith are illustrated in
In accordance with the present invention, fatty acid or fatty acid derived products are produced in a manner dependent at least in part on a malonyl-CoA dependent pathway. In accordance with certain embodiments, the malonyl-CoA dependent pathway is also a malonyl-ACP independent fatty acid production pathway, and may be used in combination with the inhibition of a microorganism's malonyl-ACP dependent fatty acid synthase pathway. In accordance with certain other embodiments of the present invention, fatty acid or fatty acid derived products are produced through a microorganism pathway that is partially malonyl-CoA dependent and partially malonyl-ACP dependent. In accordance with certain other embodiments of the present invention, fatty acid or fatty acid derived products are produced through a microorganism pathway that is initiated through the reaction of malonyl-CoA and acetyl-CoA via a CoA dependent pathway.
Referring to
The present invention herein provides genetically modified microorganisms that are modified to enable and/or improve a microorganism's ability to produce fatty acids and/or fatty acid derivatives at least in part through a malonyl-CoA dependent pathway. The malonyl-CoA dependent pathway may be independent of a malonyl-ACP pathway or may be in combination with a malonyl-ACP pathway.
In general, the genetically modified organism herein can be Clostridium, Zymomonas, Escherichia, Salmonella, Rhodococcus, Pseudomonas, Streptomyces, Bacillus, Lactobacillus, Enterococcus, Alcaligenes, Klebsiella, Paenibacillus, Arthrobacter, Corynebacterium, Brevibacterium, Pichia, Candida, Hansenula, Thraustochytrids, Bacteriophage, Saccharomyces; can be a prokaryotic cell; can be a eukaryotic cell; and/or can be a bacteria, yeast, fungi, microalgae or algae cell. Preferably the genetically modified organism is Escherichia coli.
The genetic modifications contemplated by the present invention include enhancing the organism's function in three phases of a CoA-dependent fatty acid pathway contemplated herein: (1) initiation of the fatty acid pathway; (2) chain length extension (or elongation); and (3) termination of the process once a desired chain length is achieved. These three phases are exemplified in
The first phase of the malonyl-CoA dependent pathway is reaction initiation. The reaction to produce even chain fatty acid products is initiated through the conversion of acetyl-CoA+malonyl-CoA to 3-ketobutyryl-CoA. This conversion requires a synthase—a ketobutyryl-CoA synthase. As illustrated in
In accordance with one aspect of the present invention, NphT7, a 3-ketoacyl-CoA synthase from Streptomyces sp. Strain CL190 acts as the ketobutyryl-CoA synthase that initiates fatty acid synthesis by catalyzing the condensation of acetyl-CoA with malonyl-CoA to 3-ketobutyryl-CoA and with reduction→dehydration→reduction to butyryl-CoA (C4-COA). In accordance with one aspect of the present invention, NphT7 acts as the 3-ketovaleryl-CoA synthase that initiates fatty acid synthesis by catalyzing the condensation of propionyl-CoA with malonyl-CoA to 3-ketovaleryl-CoA and with reduction→dehydration→reduction to valeryl-CoA (C5-CoA). The protein sequence for NphT7 (BAJ10048.1 GI:299758082) and its nucleotide sequence (AB540131.1 GI:299758081) are provided below (SEQ ID NO:1; SEQ ID NO:2).
In some embodiments, the 3-ketobutyryl-CoA synthase of the present invention is a homolog to a synthase comprising a protein sequence of any one of SEQ ID NOs. 1-120, as shown in Table 1 below. In some embodiments, the 3-ketobutyryl-CoA synthase of the present invention is a 3-ketoacyl-CoA synthase that comprises an amino acid sequence having at least about 70%, about 75%, about 80%, about 85%, about 90%, about 92%, about 94%, about 96%, about 98%, or about 99%, but less than 100% or about 100% homology to any one of SEQ ID NOs. 1-120. In some embodiments, the method herein comprises selecting at least two of 3-ketoacyl-CoA synthases, wherein each synthase occupies a different branch of a phylogenetic tree. In one aspect, the present invention provides a library of NphT7 homologs herein selected by a method herein.
In some embodiments, the 3-ketovaleryl-CoA synthase of the present invention is a homolog to a synthase comprising a protein sequence of any one of SEQ ID NOs. 1-120, as shown in Table 1 below. In some embodiments, the 3-ketovaleryl-CoA synthase of the present invention is a 3-ketoacyl-CoA synthase that comprises an amino acid sequence having at least about 70%, about 75%, about 80%, about 85%, about 90%, about 92%, about 94%, about 96%, about 98%, or about 99%, but less than 100% or about 100% homology to any one of SEQ ID NOs. 1-120. In some embodiments, the method herein comprises selecting at least two of 3-ketoacyl-CoA synthases, wherein each synthase occupies a different branch of a phylogenetic tree. In one aspect, the present invention provides a library of NphT7 homologs herein selected by a method herein.
perfringens str.
coelicolor A3(2)]
magnetotacticum
parahaemolyticus
kaustophilus
dehalogenans
cryohalolentis K5]
atlantica T6c]
carboxydivorans
putrefaciens CN-
acidovorans SPH-
aeruginosa NIES-
baumannii SDF]
michiganensis
sepedonicus]
zucineum
aggregans DSM
hilgardii ATCC
anulatus]
bacterium
grahamii as4aup]
botulinum D str.
cholerae AM-
lwoffii SH145]
acnes J139]
ghanaensis ATCC
aeruginosa PAb1]
tuberculosis
dentocariosa
kristjanssonii
brockii subsp.
finnii Ako-1]
scotoductus SA-
ureae ATCC
equi ATCC
vesicatoria ATCC
papyrosolvens
fimi ATCC 484]
putida S16]
stutzeri ATCC
macacae ATCC
maltophilia JV3]
marinus
oboediens
simiae CCM
necrophorum
funduliforme
cyanea NA-
azurea NA-
butzleri ED-1]
psittaci 6BC]
adhaerens HP15]
influenzae R2846]
solanacearum
peoriae KCTC
aestuarii B11]
vallismortis DV1-
gallaeciensis 2.10]
sulfurreducens
macleodii str.
ferriphilum ML-
polaris LMG
aquariorum
monocytogenes
enterica subsp.
enterica serovar
avium subsp.
baltica SH28]
solanacearum
nucleatum subsp.
polymorphum
hafniense DP7]
hydrophila SSU]
syringae pv.
opacus PD630]
bronchiseptica
aichiensis NBRC
lupini str. Lupac
liflandii 128FXT]
paraffinivorans
nanhaiticus D15-
marinus
davawensis JCM
pecorum E58]
ultunense Esp]
coralloides DSM
peoriae KCTC
fermentans DSM
Solibacter usitatus
nigrificans
glauca K62]
coralloides]
pneumophila str.
avermitilis]
maris AB-18-032]
baltica SH 1]
Methylomirabilis
oxyfera]]
marianensis DSM
exile AZM16c01]
alkaliphilus LW1]
Amoebophilus
asiaticus 5a2]
As noted above, the reaction initiation phase for even chain fatty acid products is completed by the conversion of 3-ketobutyryl-CoA to butyryl-CoA by three enzymes: a ketoacyl-CoA reductase, a hydroxyacyl-CoA dehydratase, and an enoyl-CoA reductase. For this phase, the ketoacyl-CoA reductase may be selected from the group consisting of 3-ketobutyryl-CoA reductase (e.g., fadB, a bifunctional enzyme—SEQ ID NO 183) and 3-hydroxybutyryl-CoA dehydrogenase (e.g., hbd—SEQ ID NO 271); the hydroxyacyl-CoA dehydratase may be selected from the group consisting of 3-hydroxybutyryl-CoA dehydratase (e.g., fadB, a bifunctional enzyme—SEQ ID NO 183) and enoyl-CoA hydratase (e.g., crt—SEQ ID NO 272); and the enoyl-CoA reductase may be trans-2-enoyl-reductase (e.g., ter—SEQ ID NO 275). Preferably, the bifunctional fadB is both the ketoacyl-CoA reductase and the hydroxyacyl-CoA dehydratase, or the ketoacyl-CoA reductase is hbd and the hydroxyacyl-CoA dehydratase is crt.
As noted above, the reaction initiation phase for odd chain fatty acid products is completed by the conversion of 3-ketovaleryl-CoA to valeryl-CoA by three enzymes: a ketoacyl-CoA reductase, a hydroxyacyl-CoA dehydratase, and an enoyl-CoA reductase. For this phase, the ketoacyl-CoA reductase may be selected from the group consisting of 3-ketovaleryl-CoA reductase (e.g., fadB, a bifunctional enzyme—SEQ ID NO 183) and 3-hydroxyvaleryl-CoA dehydrogenase (e.g., hbd—SEQ ID NO 271); the hydroxyacyl-CoA dehydratase may be selected from the group consisting of 3-hydroxyvaleryl-CoA dehydratase (e.g., fadB, a bifunctional enzyme—SEQ ID NO 183) and enoyl-CoA hydratase (e.g., crt—SEQ ID NO 272); and the enoyl-CoA reductase may be trans-2-enoyl-reductase (e.g., ter—SEQ ID NO 275). Preferably, the bifunctional fadB is both the ketoacyl-CoA reductase and the hydroxyacyl-CoA dehydratase, or the ketoacyl-CoA reductase is hbd and the hydroxyacyl-CoA dehydratase is crt.
In accordance with an alternative embodiment, as shown in
If a CoA-dependent elongation phase immediately follows an ACP-dependent initiation phase (see for example
Alternatively, a genetically modified microorganism may be encoded for a gene that transitions a fatty acid production pathway from an ACP-dependent pathway to a CoA-dependent pathway, or conversely from a CoA-dependent pathway to an ACP-dependent pathway, by converting any ACP intermediate to its corresponding CoA intermediate, or vice versa. For example, the genetically modified microorganism may be encoded for phaG, preferably from Pseudomonas putida KT2440, which converts 3-hydroxyacyl-ACP to 3-hydroxyacyl-CoA.
The second phase of the malonyl-CoA dependent pathway involves a cyclic process wherein the length of the carbon chain is extended by two carbons with each cycle. As illustrated in
NphT7 exhibits significant specificity for acetyl-CoA and propionyl-CoA as primers in the initiation phase, and it shows minimal activity with larger acyl-CoA chains during the elongation phase. Most 3-ketoacyl-CoA synthases that are capable of catalyzing the condensation of longer acyl-CoA chains are found in plants, mammals, yeast and other lower eukaryotes. Without a 3-ketoacyl-CoA synthase that has specificity for longer acyl-CoA, there will be no elongation of the acyl-CoA chain greater than C4-COA or C5-COA, and therefore 3-ketoacyl-CoA synthases that have specificity for longer acyl-CoA may be required.
In one aspect, the present invention provides a modified NphT7 polypeptide that functions as the ketoacyl-CoA synthase during the elongation phase in the malonyl-CoA dependent pathway. The modified NphT7 comprises an amino acid sequence having at least 70% but less than 100% or about 100% homology to SEQ ID NO:1 and one or more amino acid substitutions, deletions, or insertions, wherein the modified NphT7 polypeptide is capable of accepting an acyl-CoA substrate having a carbon chain length of C4 or greater, for example C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21 or C22. In some embodiments, the modified NphT7 polypeptide is capable of catalyzing a condensation reaction to condense an acyl-CoA substrate with a malonyl-CoA to produce a 3-ketoacyl-CoA having a carbon chain length of C6 or greater, for example C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21 or C22. In some embodiments, the modified NphT7 polypeptide comprises one or more amino acid substitutions selected from the group consisting of I147T, F217V, Y144L, V157F, G309S, G288S, a PDRP to HFLQ substitution for amino acids 86-89, I147F, I147M, I147Q, I147S, I147C, 1147E, I147N, I147W, I147D, I147R, I147P, I147L, V196G, I147G, I147H, I147K, I147V, I147A, I147Y, F217G, F217A, F217L, F217I, F217M, F217T, F217P, F217S, F217E, F217L, F217W, and any combination thereof. In some embodiments, the modified NphT7 polypeptide comprises one amino acid substitution selected from the group consisting of I147V, I147F, I147M, I147Q, I147S, I147C, 1147E, I147N, I147W, I147D, I147R, I147P, I147L, I147G, I147H, I147K, I147A, I147Y, and F217V. In some embodiments, the modified NphT7 polypeptide comprises two amino acid substitutions selected from the group consisting of I147T and F217V, I147T and Y144L, I147T and V196G, I147F and F217V, I147M and F217V, I147S and F217V, I147T and HFLQ, I147T and V157F, I147T and F217G, I147T and F217A, I147T and F217L, I147T and F217I, I147T and F217M, I147T and F217P, I147T and F217S, I147T and F217E, I147S and F217G, I147S and F217A, I147S and F217L, I147S and F217I, I147S and F217M, I147S and F217W, I147S and F217S, I147S and F217E, I147S and F217K, I147F and F217A, I147F and F217L, I147F and F217I, I147F and F217M, I147F and F217P, I147F and F217E, I147M and F217G, I147M and F217A, I147M and F217L, I147M and F217I, I147M and F217M, I147M and F217P, I147M and F217S, I147M and F217E, and I147M and F217K. In some embodiments, the modified NphT7 polypeptide of any embodiment, comprising three amino acid substitutions selected from the group consisting of (Y144L, I147T, and F217V), (I147T, F217V, and HFLQ), (I147T, V147F, and F217V), and (Y144L, I147T, and V157F). In some embodiments, the modified NphT7 polypeptide comprises one or more amino acid substitutions at a position selected from the group consisting of Ser84, Val114, Gly288, Ile194, Gly318, Thr85, Gln90, Val196, Tyr144, Phe159, Ile147, Phe217, and any combination thereof. In some embodiments, the modified NphT7 polypeptide comprises an I147T amino acid substitution. In some embodiments, the modified NphT7 polypeptide comprises an F217V amino acid substitution. In some embodiments, the modified NphT7 polypeptide comprises two or more amino acid substitutions, deletions, or insertions, such as an I147T amino acid substitution and an F217V amino acid substitution. In some embodiments, the modified polypeptide is isolated and purified.
In one aspect, the present invention provides an isolated and purified polynucleotide encoding a modified NphT7 polypeptide. In some embodiments, the isolated and purified polynucleotide comprises a nucleic acid sequence having at least 70% but less than 100% or about 100% homology or complementarity to SEQ ID NO:2, wherein the polynucleotide encodes a modified NphT7 polypeptide of SEQ ID NO:1 having one or more amino acid substitutions, deletions, or insertions, wherein the modified NphT7 polypeptide is capable of accepting an acyl-CoA substrate having a carbon chain length of C4 or greater, for example C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21 or C22. In some embodiments, the isolated and purified polynucleotide encodes a modified NphT7 polypeptide capable of catalyzing a condensation reaction to condense an acyl-CoA substrate with a malonyl-CoA to produce a 3-ketoacyl-CoA having a carbon chain length of C6 or greater, for example C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21 or C22. The isolated and purified polynucleotide of any embodiment that encodes a modified NphT7 polypeptide comprising one or more amino acid substitutions selected from the group consisting of I147T, F217V, Y144L, V157F, G309S, G288S, a PDRP to HFLQ substitution for amino acids 86-89, I147F, I147M, I147Q, I147S, I147C, I147E, I147N, I147W, I147D, I147R, I147P, I147L, V196G, I147G, I147H, I147K, I147V, I147A, I147Y, F217G, F217A, F217L, F217I, F217M, F217T, F217P, F217S, F217E, F217L, F217W, and any combination thereof. In some embodiments, the isolated and purified polynucleotide encodes a modified NphT7 polypeptide comprising one amino acid substitution selected from the group consisting of I147V, I147F, I147M, I147Q, 1147S, I147C, 1147E, I147N, I147W, I147D, I147R, I147P, I147L, I147G, I147H, I147K, I147A, I147Y, and F217V. In some embodiments, the isolated and purified polynucleotide encodes a modified NphT7 polypeptide comprising two amino acid substitutions selected from the group consisting of I147T and F217V, I147T and Y144L, I147T and V196G, I147F and F217V, I147M and F217V, I147S and F217V, I147T and HFLQ, I147T and V157F, I147T and F217G, I147T and F217A, I147T and F217L, I147T and F217I, I147T and F217M, I147T and F217P, I147T and F217S, I147T and F217E, I147S and F217G, I147S and F217A, I147S and F217L, I147S and F217I, I147S and F217M, I147S and F217W, I147S and F217S, I147S and F217E, I147S and F217K, I147F and F217A, I147F and F217L, I147F and F217I, I147F and F217M, I147F and F217P, I147F and F217E, I147M and F217G, I147M and F217A, I147M and F217L, I147M and F217I, I147M and F217M, I147M and F217P, I147M and F217S, I147M and F217E, and I147M and F217K. In some embodiments, the isolated and purified polynucleotide herein encodes a modified NphT7 polypeptide comprising three amino acid substitutions selected from the group consisting of (Y144L, I147T, and F217V), (I147T, F217V, and HFLQ), (I147T, V147F, and F217V), and (Y144L, I147T, and V157F). In some embodiments, the isolated and purified polynucleotide herein encodes a modified NphT7 polypeptide comprising one or more amino acid substitutions at a position selected from the group consisting of Ser84, Val114, Gly288, Ile194, Gly318, Thr85, Gln90, Val196, Tyr144, Phe159, Ile147, Phe217, and any combination thereof. In some embodiments, the isolated and purified polynucleotide herein encodes a modified NphT7 polypeptide comprising an I147T amino acid substitution. In some embodiments, the isolated and purified polynucleotide herein encodes a modified NphT7 polypeptide comprising an F217V amino acid substitution. In some aspects, the isolated and purified polynucleotide herein encodes a modified NphT7 polypeptide comprising two or more amino acid substitutions, deletions, or insertions. In some aspects, the isolated and purified polynucleotide herein encodes a modified NphT7 polypeptide, comprising an I147T amino acid substitution and an F217V amino acid substitution. In some embodiments, the isolated and purified polynucleotide herein is a RNA, mRNA, DNA, or cDNA. In some embodiments, the isolated and purified polynucleotide herein is a synthetic polynucleotide. In some embodiments, the isolated and purified polynucleotide herein is synthetic: RNA, mRNA, DNA, or cDNA.
In one aspect, the present invention provides for a ketoacyl-CoA synthase that is active during the elongation phase in the malonyl-CoA dependent pathway, wherein the ketoacyl-CoA synthase is selected from the group consisting of npht7 F217V, npht7 I147T, synthase III, synthase IV, synthase V, and synthase VI; wherein npht7 F217V and/or npht7 I147T catalyzes a reaction adding the 5th and/or 6th carbon in the elongation, npht7 F217V, npht7 I147T, and/or synthase III catalyzes a reaction adding the 7th and/or 8th carbon in the elongation, npht7 F217V, npht7 I147T, synthase III, synthase IV, and/or synthase V catalyzes a reaction adding the 9th and/or 10th carbon in the elongation, or wherein npht7 F217V, npht7 I147T, synthase III, synthase IV, synthase V, and/or synthase VI catalyzes a reaction adding the 9th and/or higher number carbon in the elongation.
Referring again to
For the elongation phase, the ketoacyl-CoA reductase may be selected from the group consisting of 3-ketoacyl-CoA reductase (e.g., fadB, a bifunctional enzyme—SEQ ID NO 183) and 3-hydroxyacyl-CoA dehydrogenase (e.g., hbd—SEQ ID NO 271); the hydroxyacyl-CoA dehydratase may be selected from the group consisting of 3-hydroxyacyl-CoA dehydratase (e.g., fadB, a bifunctional enzyme—SEQ ID NO 183) and enoyl-CoA hydratase (e.g., crt—SEQ ID NO 272); and the enoyl-CoA reductase may be trans-2-enoyl-reductase (e.g., ter—SEQ ID NO 275). Preferably, the bifunctional fadB is both the ketoacyl-CoA reductase and the hydroxyacyl-CoA dehydratase, or the ketoacyl-CoA reductase is hbd and the hydroxyacyl-CoA dehydratase is crt.
The elongation phase ends with a termination step once the desired chain length is achieved. In one aspect of the invention, the genetically modified microorganism encodes an enzyme capable of terminating an acyl elongation cycle substantially at a desired chain length or substantially within a relatively narrow distribution of chain lengths (i.e., a distribution of 2-4 carbons—e.g., C8-C10, C8-C12, C10-C12, C10-C14, etc.). In another aspect of the invention, the termination enzyme is a thioesterase such as an acyl-CoA esterase, and the microorganism produces a fatty acid. Suitable thioesterases include tesA—SEQ ID NO 277, ‘tesA—SEQ ID NO 278, tesB—SEQ ID NO 279, yciA—SEQ ID NO 280, ybgC—SEQ ID NO 281, ybfF—SEQ ID NO 282, fadM—SEQ ID NO 283, AtTE—SEQ ID NO 284, CpTE—SEQ ID NO 285, CperfTE—SEQ ID NO 286, LpTE—SEQ ID NO 287, and PA2801TE—SEQ ID NO 288, and combinations thereof. Alternatively, the termination enzyme is a wax ester synthase and the microorganism produces a fatty ester. Suitable wax ester synthase include Maq1—SEQ ID NO 289, Pcry1—SEQ ID NO 290, Rjos1—SEQ ID NO 291, and Abork1—SEQ ID NO 292. Alternatively, it is within the skill of the art to add other known termination enzyme(s) that will enable the genetically modified microorganism to produce alternative fatty acid derivatives such as, for example, a fatty alcohol, a fatty aldehyde, a fatty alkene, a fatty amide, a fatty alkane, or a fatty diacid. By way of example, the termination enzyme may be a fatty acid or acyl-CoA reductase that catalyzes the production of a fatty alcohol or fatty aldehyde, or an aldehyde decarbonylase that catalyzes the production of fatty aldehyde, or an aldehyde decarbonylase together with an acyl-ACP reductase or an acyl-CoA reductase that catalyzes the production of an alkane.
In accordance with one aspect of the invention, the genetically modified microorganism is engineered to produce a fatty acid or fatty acid derivative product having substantially a specific chain length or having a substantially narrow distribution of chain lengths (i.e., 2-4 carbons). Preferably, at least 50%, 60%, 70%, 80%, or 90% of the fatty acids or fatty acid derivative produced by the genetically modified microorganism of the present invention is of a desired chain length or within a desired narrow distribution of chain lengths. Applicants have determined that such specificity may be achieved through engineering a microorganism to encode for various combinations of genes that will lead to the production of fatty acids and fatty acid derivatives having specific chain lengths. Table 2 below sets forth certain unique combinations of genes that lead to the production of products having the carbon chain lengths indicated in Table 2.
In accordance with one aspect of the invention, there is provided a genetically modified microorganism having encoded therein the genes included in Table 2 for a given pathway, wherein such microorganism is capable of producing a fatty acid or fatty acid derivative having a carbon chain length indicated in Table 2 for such pathway. There is also provided a genetically modified microorganism having encoded therein the genes included in Table 2 above for a combination of pathways, wherein the microorganism is capable of producing fatty acids or fatty acid derivatives within a substantially narrow distribution of chain lengths corresponding to the carbon chain lengths indicated in Table 2 for such combination of pathways. For example, there is provided a genetically modified microorganism comprising NphT7, fadB, ter, AtTE, and tesA (C10 pathway A and C12 pathway A), wherein said microorganism is capable of producing a fatty acid composition comprising C10 and C12 fatty acids.
In another aspect, applicants have discovered that chain length specificity can be controlled by utilizing certain enzymes from certain specific species of organisms. Accordingly, the present invention provides one or more isolated and purified polynucleotides comprising exogenous nucleic acid molecules encoding proteins comprising a 3-oxoacyl-(acyl carrier protein) synthase III from a species selected from the group consisting of Alishewanella aestuarii B11, Arcobacter butzleri ED-1, Clostridiales bacterium 1_7_47 FAA, Gluconacetobacter oboediens 174Bp2, Gordonia aichiensis NBRC 108223, Mesorhizobium sp. STM 4661, Pelosinus fermentans DSM 17108, Phaeobacter gallaeciensis 2.10, Ralstonia solanacearum Po82, Saccharomonospora azurea NA-128, Saccharomonospora glauca K62, and Verrucosispora maris AB-18-032, wherein the proteins encoded by the polynucleotides are capable of producing a fatty acid.
In some embodiments, the 3-oxoacyl-(acyl carrier protein) synthase III is from a species selected from the group consisting of Pelosinus fermentans DSM 17108, Saccharomonospora glauca K62, Verrucosispora maris AB-18-032, and Clostridiales bacterium 1_7_47 FAA, and wherein the proteins encoded by the polynucleotides are capable of producing an acetyl-CoA. In some embodiments, the 3-oxoacyl-(acyl carrier protein) synthase III is from a species selected from the group consisting of Saccharomonospora glauca K62, Saccharomonospora azurea NA-128, Mesorhizobium sp. STM 4661, and Clostridiales bacterium 1_7_47 FAA, and wherein the proteins encoded by the polynucleotides are capable of producing a four carbon fatty acid. In some embodiments, the 3-oxoacyl-(acyl carrier protein) synthase III is from a species selected from the group consisting of Gordonia aichiensis NBRC 108223, Arcobacter butzleri ED-1, Clostridiales bacterium 1_7_47 FAA, Saccharomonospora glauca K62, and Ralstonia solanacearum Po82, and wherein the proteins encoded by the polynucleotides are capable of producing a six carbon fatty acid. In some embodiments, the 3-oxoacyl-(acyl carrier protein) synthase III is from a species selected from the group consisting of Gordonia aichiensis NBRC 108223, Gluconacetobacter oboediens 174Bp2, Arcobacter butzleri ED-1, Ralstonia solanacearum Po82, and Phaeobacter gallaeciensis 2.10, and wherein the proteins encoded by the polynucleotides are capable of producing an eight carbon fatty acid. In some embodiments, the 3-oxoacyl-(acyl carrier protein) synthase III is from Alishewanella aestuarii B11, and wherein the proteins encoded by the polynucleotides are capable of producing a ten carbon fatty acid.
As discussed above, certain aspects the present invention relate to microorganisms that are genetically modified to produce fatty acids and fatty acid derivatives through a malonyl-CoA dependent pathway that is also a malonyl-ACP independent pathway. This aspect of the invention may be used in combination with the inhibition of a microorganism's malonyl-ACP dependent fatty acid synthase pathway through one or more genetic modifications to reduce the activity of enzymes encoded by one or more of the microorganism's malonyl-ACP dependent fatty acid synthase system genes. The compositions may be used in the methods and systems of the present invention.
In many microorganism cells the fatty acid synthase system comprises polypeptides that have the following enzymatic activities: malonyl-CoA-acyl carrier protein (ACP) transacylase; 3-ketoacyl-ACP synthase; 3-ketoacyl-ACP reductase; 3-hydroxyacyl-ACP dehydratase; 3-hydroxyacyl-ACP dehydratase; and enoyl-ACP reductase. In various embodiments nucleic acid sequences that encode temperature-sensitive forms of these polypeptides may be introduced in place of the native enzymes, and when such genetically modified microorganisms are cultured at elevated temperatures (at which these thermolabile polypeptides become inactivated, partially or completely, due to alterations in protein structure or complete denaturation), there is observed an increase in flux through the malonyl-CoA dependent pathway and a decrease in flux through the malonyl-ACP dependent pathway.
In E. coli, these temperature-sensitive mutant genes could include fabIts(S241F), fabBts(A329V) or fabDts(W257Q). In other embodiments other types of genetic modifications may be made to otherwise modulate, such as lower, enzymatic activities of one or more of these polypeptides. In various embodiments, a result of such genetic modifications is to shift malonyl-CoA utilization so that there is a reduced conversion of malonyl-CoA to fatty acids via the native pathway, overall biomass, and proportionally greater conversion of carbon source to a chemical product including a fatty acid or fatty acid derived product via a malonyl-CoA dependent, and in some cases a malonyl-ACP independent route. In various embodiments, the specific productivity for the microbially produced chemical product is unexpectedly high. Also, additional genetic modifications, such as to increase malonyl-CoA production, may be made for certain embodiments.
One enzyme, enoyl-acyl carrier protein reductase (EC No. 1.3.1.9, also referred to as enoyl-ACP reductase) is a key enzyme for fatty acid biosynthesis from malonyl-CoA. In Escherichia coli this enzyme, FabI, is encoded by the gene fabI (See “Enoyl-Acyl Carrier Protein (fabI) Plays a Determinant Role in Completing Cycles of Fatty Acid Elongation in Escherichia coli,” Richard J. Heath and Charles O. Rock, J. Biol. Chem. 270:44, pp. 26538-26543 (1995), incorporated by reference for its discussion of fabI and the fatty acid synthase system).
The present invention may utilize a microorganism that is provided with a nucleic acid sequence (polynucleotide) that encodes a polypeptide having enoyl-ACP reductase enzymatic activity that may be modulated during a fermentation event. For example, a nucleic acid sequence encoding a temperature-sensitive enoyl-ACP reductase may be provided in place of the native enoyl-ACP reductase, so that an elevated culture temperature results in reduced enzymatic activity, which then results in a shifting utilization of malonyl-CoA to production of a desired chemical product. One such sequence is a mutant temperature-sensitive fabI (fabITS) of E. coli or the fabIts(S241F) (SEQ ID NO 141). This enzyme may exhibit reduced enzymatic activity at temperatures above 30° C. but normal enzymatic activity at 30° C., so that elevating the culture temperature to, for example to 34° C., 35° C., 36° C., 37° C. or even 42° C., reduces enzymatic activity of enoyl-ACP reductase. In such case, more malonyl-CoA is converted to a fatty acid or fatty acid derived product or another chemical product through the non-native pathway under the current invention than at 30° C., where conversion of malonyl-CoA to fatty acids through its native fatty acid pathway is not impeded by a less effective enoyl-ACP reductase.
It is appreciated that nucleic acid and amino acid sequences for enoyl-ACP reductase in species other than E. coli are readily obtained by conducting homology searches in known genomics databases, such as BLASTN and BLASTP. Approaches to obtaining homologues in other species and functional equivalent sequences are described herein. Accordingly, it is appreciated that the present invention may be practiced by one skilled in the art for many microorganism species of commercial interest.
Approaches other than a temperature-sensitive enoyl-ACP reductase may be employed as known to those skilled in the art, such as, but not limited to, replacing a native enoyl-ACP or enoyl-CoA reductase with a nucleic acid sequence that includes an inducible promoter for this enzyme, so that an initial induction may be followed by no induction, thereby decreasing enoyl-ACP or enoyl-CoA reductase enzymatic activity after a selected cell density is attained. For example, a genetic modification may be made to reduce the enzymatic activity of the enoyl-ACP reductase gene (e.g., fabI in E. coli). In such example the promoter may be induced (such as with isopropyl-μ-D-thiogalactopyranoiside (IPTG)) during a first phase of a method herein, and after the IPTG is exhausted, removed or diluted out the second step, of reducing enoyl-ACP reductase enzymatic activity, may begin. Other approaches may be applied to control enzyme expression and activity such as are described herein and/or known to those skilled in the art. For example promoters that are turned on in response to phosphate depletion may be used to controllably express desired genes. Such promoters could include the yibD or pstS gene promoters in E. coli.
Without being bound to a particular theory, it is believed that reducing the enzymatic activity of enoyl-ACP reductase (and/or of other enzymes of the fatty acid synthase system) in a microorganism leads to an accumulation and/or shunting of malonyl-CoA, a metabolic intermediate upstream of the enzyme, and such malonyl-CoA may then be converted to a chemical product for which the microorganism cell comprises a metabolic pathway that utilizes malonyl-CoA. In certain compositions, methods and systems of the present invention the reduction of enzymatic activity of enoyl-ACP reductase (or, more generally, of the fatty acid synthase system) is made to occur after a sufficient cell density of a genetically modified microorganism is attained. This bi-phasic culture approach balances a desired quantity of biocatalyst, in the cell biomass which supports a particular production rate, with yield, which may be partly attributed to having less carbon be directed to cell mass after the enoyl-ACP reductase activity (and/or activity of other enzymes of the fatty acid synthase system) is/are reduced. This results in a shifting net utilization of malonyl-CoA, thus providing for greater carbon flux to a desired chemical product.
Once the modulation is in effect to decrease the noted enzymatic activity(ies), each respective enzymatic activity so modulated may be reduced by at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, or at least 90 percent compared with the activity of the native, non-modulated enzymatic activity (such as in a cell or isolated). Similarly, the conversion of malonyl-CoA to fatty acyl-ACP or molecules may be reduced by at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, or at least 90 percent compared with such conversion in a non-modulated cell or other system. Likewise, the conversion of malonyl-CoA to fatty acid molecules through its native pathway may be reduced by at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, or at least 90 percent compared with such conversion in a non-modulated cell or other system.
The genetic modifications described hereinabove may be combined with various additional genetic modifications to further enhance production of a desired chemical product. Such additional genetic modifications may result in a variety of beneficial attributes, such as increasing glucose uptake, decreasing consumption of key intermediates by alternative reaction pathways leading to undesirable by-products, and driving carbon flux to malonyl-CoA. Certain of these additional genetic modifications are set forth in Table 3.
E. coli
In addition to the above-described genetic modifications, in various embodiments genetic modifications also are provided to increase the pool and availability of the cofactor NADPH, and/or, consequently, the NADPH/NADP+ ratio. For example, in various embodiments for E. coli, this may be done by increasing activity, such as by genetic modification, of one or more of the following genes: pgi (in a mutated form), pntAB, overexpressed, gapA:gapN substitution/replacement, and disrupting or modifying a soluble transhydrogenase such as sthA, and/or genetic modifications of one or more of zwf, gnd, and edd.
Any of the genetic modifications described herein may be provided to species not having such functionality, or having a less than desired level of such functionality.
More generally, and depending on the particular metabolic pathways of a microorganism selected for genetic modification, any subgroup of genetic modifications may be made to decrease cellular production of fermentation product(s) selected from the group consisting of acetate, acetoin, acetone, acrylic, malate, fatty acid ethyl esters, glycerolipids, lipids, isoprenoids, glycerol, ethylene glycol, ethylene, propylene, butylene, isobutylene, ethyl acetate, vinyl acetate, other acetates, 1,4-butanediol, 2,3-butanediol, butanol, isobutanol, sec-butanol, butyrate, isobutyrate, 2-OH-isobutryate, 3-OH-butyrate, ethanol, isopropanol, D-lactate, L-lactate, pyruvate, itaconate, levulinate, glucarate, glutarate, caprolactam, adipic acid, propanol, isopropanol, fusel alcohols, and 1,2-propanediol, 1,3-propanediol, formate, fumaric acid, propionic acid, succinic acid, valeric acid, and maleic acid. Gene deletions may be made as disclosed generally herein, and other approaches may also be used to achieve a desired decreased cellular production of selected fermentation products.
In some embodiments, additional genetic modification is associated with a genotype or an enzyme selected from the group listed in Table 4-Table 13 below. The amino acid sequences of these enzymes are shown in Table 14.
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
H. elongata
H. elongata
H. elongata
H. elongata
E. coli
E. coli
E. coli
E. coli
Arthrobacter
E. coli
Synechococcus
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
Arthrobacter
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
Streptomyces Sp
Staphylococcus
aureus MW2
Bacillus subtilis
Pseudomonas
aeruginosa PAO1
Mycobacterium
tuberculosis H37Rv
Rhodothermus
marinus
Streptomyces
davawensis
Chlamydophila
pecorum E58
Clostridium
ultunense Esp
Corallococcus
coralloides DSM
Desmospora sp.
Paenibacillus
peoriae KCTC 3763
Pelosinus
fermentans DSM
Candidatus
Solibacter usitatus
Desulfotomaculum
nigrificans DSM
Saccharomonospora
glauca K62
Corallococcus
coralloides
Legionella
pneumophila str.
Streptomyces
avermitilis
Verrucosispora
maris AB-18-032
Rhodopirellula
baltica SH 1
Candidatus
methylomirabilis
oxyfera
Thermaerobacter
marianensis
Caldisericum exile
Indibacter
alkaliphilus LW1
Candidatis
amoebophilus
asiaticus 5a2
Flavobacterium sp.
Anaeromyxobacter
dehalogenans 2CP-
Microcystis
aeruginosa NIES-
Chloroflexus
aggregans DSM
Lactobacillus
hilgardii ATCC
Bartonella grahamii
Clostridium
botulinum D str.
Vibrio cholerae
Propionibacterium
acnes J139
Streptomyces
ghanaensis ATCC
Veillonella sp.
Streptomyces sp. C
Streptomyces sp.
Saccharomonospora
azurea NA-128
Ralstonia
solanacearum Po82
Frankia sp. QA3
Alishewanella
aestuarii B11
Brevibacillus sp.
Sphingomonas sp.
Alteromonas
macleodii str.
Leptospirillum
ferriphilum ML-04
Glaciecola polaris
Listeria
monocytogenes J1-
Mycobacterium
avium subsp.
paratuberculosis
Fusobacterium
nucleatum subsp.
polymorphum
Mycobacterium
liflandii 128FXT
Mesorhizobium sp.
Streptomyces
coelicolor A3(2)
Clostridiales
bacterium
Ruegeria sp. R11
Rothia dentocariosa
Caldicellulosiruptor
kristjanssonii
Thermus
scotoductus SA-01
Geobacter sp. M18
Rhodococcus equi
Clostridium
papyrosolvens
Cellulomonas fimi
Neisseria macacae
Rhodothermus
marinus
Gluconacetobacter
oboediens 174Bp2
Halomonas sp.
Saccharomonospora
cyanea NA-134
Arcobacter butzleri
Marinobacter
adhaerens HP15
Phaeobacter
gallaeciensis 2.10
Aeromonas
hydrophila SSU
Rhodococcus
opacus PD630
Gordonia aichiensis
Acinetobacter sp.
Pseudomonas
aeruginosa PAO1
Pseudomonas
aeruginosa PA7
Clostridium
beijerinckii
Clostridium
acetobutylicum
Pseudomonas
putida
Rattus norvegicus
Treponema
denticola TDE0597
Streptomyces
collinus
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
E. coli
Anaerococcus
tetradius
Cuphea
palustris
Clostridium
perfringens
Lactobacillus
plantarum
Pseudomonas
aeruginosa
Marinobacter aquaeolei VT8
Psychrobacter cryohalolentis
Rhodococcus jostii RHA1
Alcanivorax borkumensis
E. coli unless
Salmonella
enterica subsp
typhimirium
Cupriavides
necator
sphaeroides
Cupriavides
necator
sphaeroides
Pseudomonas
stutzeri phaC1
Pseudomonas
oleovorans
Pseudomonas
aeruginosa
Streptomycs
coelicolor
Streptomycs
coelicolor
coli str. K-12 substr.
coli str. K-12 substr.
coli str. K-12 substr.
coli str. K-12 substr.
coli str. K-12 substr.
coli str. K-12 substr.
coli str. K-12 substr.
coli str. K-12 substr.
coli str. K-12 substr.
coli str. K-12 substr.
coli]
coli]
V
ISLVKLLHAIEVPLCVISVFKYSVANFDKRL
coli str. K-12 substr.
coli str. K-12 substr.
coli str. K-12 substr.
coli str. K-12 substr.
aeruginosa PAO1]
tuberculosis H37Rv]
marinus SG0.5JP17-
davawensis JCM
pecorum E58]
coralloides DSM
nigrificans DSM 574]
glauca K62]
coralloides]
pneumophila str.
avermitilis]
baltica SH 1]
Methylomirabilis
marianensis DSM
alkaliphilus LW1]
Amoebophilus
dehalogenans 2CP-C]
aeruginosa NIES-843]
aggregans DSM 9485]
hilgardii ATCC 8290]
botulinum D str. 1873]
acnes JI39]
ghanaensis ATCC
azurea NA-128]
solanacearum Po82]
aestuarii B11
macleodii str. ‘English
ferriphilum ML-04]
polaris LMG 21857]
monocytogenes J1-
avium subsp.
nucleatum subsp.
polymorphum F0401]
liflandii 128FXT]
coelicolor A3(2)]
kristjanssonii
papyrosolvens DSM
marinus SG0.5JP17-
oboediens 174Bp2]
cyanea NA-134]
adhaerens HP15]
gallaeciensis 2.10]
hydrophila SSU]
aeruginosa PAO1]
aeruginosa PA7]
beijerinckii]
Clostridium
acetobutylicum
norvegicus]
denticola]
coli str. K-12 substr.
coli str. K-12 substr.
tetradius ATCC
perfringens ATCC
plantarum WCFS1]
aeruginosa PAO1]
aquaeolei VT8]
cryohalolentis K5]
borkumensis SK2]
Typhi str. CT18]
sphaeroides 2.4.1]
sphaeroides 2.4.1]
stutzeri]
oleovorans]
aeruginosa PAO1]
Some amino acids in amino acid sequences can be varied without significant effect on the structure or function of proteins. Variants included can constitute deletions, insertions, inversions, repeats, and type substitutions so long as the indicated enzyme activity is not significantly adversely affected. Guidance concerning which amino acid changes are likely to be phenotypically silent can be found, inter alia, in Bowie, J. U., et al., “Deciphering the Message in Protein Sequences: Tolerance to Amino Acid Substitutions,” Science 247:1306-1310 (1990). In various embodiments polypeptides obtained by the expression of the polynucleotide molecules of the present invention may have at least approximately 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to one or more amino acid sequences encoded by the genes and/or nucleic acid sequences described herein for the fatty acid or fatty acid derived product tolerance-related and biosynthesis pathways.
It will be appreciated by those skilled in the art that amino acids homologous to those described herein are within the scope of the present invention. It will be appreciated that amino acid “homology” includes conservative substitutions, i.e. those that substitute a given amino acid in a polypeptide by another amino acid of similar characteristics. Typically seen as conservative substitutions are the following replacements: replacements of an aliphatic amino acid such as Ala, Val, Leu and Ile with another aliphatic amino acid; replacement of a Ser with a Thr or vice versa; replacement of an acidic residue such as Asp or Glu with another acidic residue; replacement of a residue bearing an amide group, such as Asn or Gln, with another residue bearing an amide group; exchange of a basic residue such as Lys or Arg with another basic residue; and replacement of an aromatic residue such as Phe or Tyr with another aromatic residue.
For all nucleic acid and amino acid sequences provided herein, it is appreciated that conservatively modified variants of these sequences are included, and are within the scope of the invention in its various embodiments. Functionally equivalent nucleic acid and amino acid sequences (functional variants), which may include conservatively modified variants as well as more extensively varied sequences, which are well within the skill of the person of ordinary skill in the art, and microorganisms comprising these, also are within the scope of various embodiments of the invention, as are methods and systems comprising such sequences and/or microorganisms. In various embodiments, nucleic acid sequences encoding sufficiently homologous proteins or portions thereof are within the scope of the invention. More generally, nucleic acids sequences that encode a particular amino acid sequence employed in the invention may vary due to the degeneracy of the genetic code, and nonetheless fall within the scope of the invention. Table 15 provides a summary of similarities among amino acids, upon which conservative and less conservative substitutions may be based, and also various codon redundancies that reflect this degeneracy.
Stop Codons
Also, variants and portions of particular nucleic acid sequences, and respective encoded amino acid sequences recited herein may be exhibit a desired functionality, e.g., enzymatic activity at a selected level, when such nucleic acid sequence variant and/or portion contains a 15 nucleotide sequence identical to any 15 nucleotide sequence set forth in the nucleic acid sequences recited herein including, without limitation, the sequence starting at nucleotide number 1 and ending at nucleotide number 15, the sequence starting at nucleotide number 2 and ending at nucleotide number 16, the sequence starting at nucleotide number 3 and ending at nucleotide number 17, and so forth. It will be appreciated that the invention also provides isolated nucleic acid that contains a nucleotide sequence that is greater than 15 nucleotides (e.g., 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more nucleotides) in length and identical to any portion of the sequence set forth in nucleic acid sequences recited herein. For example, the invention provides isolated nucleic acid that contains a 25 nucleotide sequence identical to any 25 nucleotide sequence set forth in any one or more (including any grouping of) nucleic acid sequences recited herein including, without limitation, the sequence starting at nucleotide number 1 and ending at nucleotide number 25, the sequence starting at nucleotide number 2 and ending at nucleotide number 26, the sequence starting at nucleotide number 3 and ending at nucleotide number 27, and so forth. Additional examples include, without limitation, isolated nucleic acids that contain a nucleotide sequence that is 50 or more nucleotides (e.g., 100, 150, 200, 250, 300, or more nucleotides) in length and identical to any portion of any of the sequences disclosed herein. Such isolated nucleic acids can include, without limitation, those isolated nucleic acids containing a nucleic acid sequence represented in any one section of discussion and/or examples, such as regarding a fatty acid or fatty acid derived product production pathways, nucleic acid sequences encoding enzymes of the fatty acid synthase system, or a fatty acid or fatty acid derived product tolerance. For example, the invention provides an isolated nucleic acid containing a nucleic acid sequence listed herein that contains a single insertion, a single deletion, a single substitution, multiple insertions, multiple deletions, multiple substitutions, or any combination thereof (e. g., single deletion together with multiple insertions). Such isolated nucleic acid molecules can share at least 60, 65, 70, 75, 80, 85, 90, 95, 97, 98, or 99 percent sequence identity with a nucleic acid sequence listed herein (i.e., in the sequence listing).
Additional examples include, without limitation, isolated nucleic acids that contain a nucleic acid sequence that encodes an amino acid sequence that is 50 or more amino acid residues (e.g., 100, 150, 200, 250, 300, or more amino acid residues) in length and identical to any portion of an amino acid sequence listed or otherwise disclosed herein.
In addition, the invention provides isolated nucleic acid that contains a nucleic acid sequence that encodes an amino acid sequence having a variation of an amino acid sequence listed or otherwise disclosed herein. For example, the invention provides isolated nucleic acid containing a nucleic acid sequence encoding an amino acid sequence listed or otherwise disclosed herein that contains a single insertion, a single deletion, a single substitution, multiple insertions, multiple deletions, multiple substitutions, or any combination thereof (e.g., single deletion together with multiple insertions). Such isolated nucleic acid molecules can contain a nucleic acid sequence encoding an amino acid sequence that shares at least 60, 65, 70, 75, 80, 85, 90, 95, 97, 98, or 99 percent sequence identity with an amino acid sequence listed or otherwise disclosed herein.
Examples of properties that provide the bases for conservative and other amino acid substitutions are exemplified in Table 15. Accordingly, one skilled in the art may make numerous substitutions to obtain an amino acid sequence variant that exhibits a desired functionality. BLASTP, CLUSTALP, and other alignment and comparison tools may be used to assess highly conserved regions, to which fewer substitutions may be made (unless directed to alter activity to a selected level, which may require multiple substitutions). More substitutions may be made in regions recognized or believed to not be involved with an active site or other binding or structural motif. In accordance with Table 15, for example, substitutions may be made of one polar uncharged (PU) amino acid for a polar uncharged amino acid of a listed sequence, optionally considering size/molecular weight (i.e., substituting a serine for a threonine). Guidance concerning which amino acid changes are likely to be phenotypically silent can be found, inter alia, in Bowie, J. U., et Al., “Deciphering the Message in Protein Sequences: Tolerance to Amino Acid Substitutions,” Science 247:1306-1310 (1990). This reference is incorporated by reference for such teachings, which are, however, also generally known to those skilled in the art. Recognized conservative amino acid substitutions comprise (substitutable amino acids following each colon of a set): ala:ser; arg:lys; asn:gln or his; asp:glu; cys:ser; gln:asn; glu:asp; gly:pro; his:asn or gln; ile:leu or val; leu:ile or val; lys: arg or gln or glu; met:leu or ile; phe:met or leu or tyr; ser:thr; thr:ser; trp:tyr; tyr:trp or phe; val:ile or leu.
It is noted that codon preferences and codon usage tables for a particular species can be used to engineer isolated nucleic acid molecules that take advantage of the codon usage preferences of that particular species. For example, the isolated nucleic acid provided herein can be designed to have codons that are preferentially used by a particular microorganism of interest. Numerous software and sequencing services are available for such codon-optimizing of sequences.
The invention provides polypeptides that contain the entire amino acid sequence of an amino acid sequence listed or otherwise disclosed herein. In addition, the invention provides polypeptides that contain a portion of an amino acid sequence listed or otherwise disclosed herein. For example, the invention provides polypeptides that contain a 15 amino acid sequence identical to any 15 amino acid sequence of an amino acid sequence listed or otherwise disclosed herein including, without limitation, the sequence starting at amino acid residue number 1 and ending at amino acid residue number 15, the sequence starting at amino acid residue number 2 and ending at amino acid residue number 16, the sequence starting at amino acid residue number 3 and ending at amino acid residue number 17, and so forth. It will be appreciated that the invention also provides polypeptides that contain an amino acid sequence that is greater than 15 amino acid residues (e. g., 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more amino acid residues) in length and identical to any portion of an amino acid sequence listed or otherwise disclosed herein For example, the invention provides polypeptides that contain a 25 amino acid sequence identical to any 25 amino acid sequence of an amino acid sequence listed or otherwise disclosed herein including, without limitation, the sequence starting at amino acid residue number 1 and ending at amino acid residue number 25, the sequence starting at amino acid residue number 2 and ending at amino acid residue number 26, the sequence starting at amino acid residue number 3 and ending at amino acid residue number 27, and so forth. Additional examples include, without limitation, polypeptides that contain an amino acid sequence that is 50 or more amino acid residues (e.g., 100, 150, 200, 250, 300 or more amino acid residues) in length and identical to any portion of an amino acid sequence listed or otherwise disclosed herein. Further, it is appreciated that, per above, a 15 nucleotide sequence will provide a 5 amino acid sequence, so that the latter, and higher-length amino acid sequences, may be defined by the above-described nucleotide sequence lengths having identity with a sequence provided herein.
In addition, the invention provides polypeptides that an amino acid sequence having a variation of the amino acid sequence set forth in an amino acid sequence listed or otherwise disclosed herein. For example, the invention provides polypeptides containing an amino acid sequence listed or otherwise disclosed herein that contains a single insertion, a single deletion, a single substitution, multiple insertions, multiple deletions, multiple substitutions, or any combination thereof (e.g., single deletion together with multiple insertions). Such polypeptides can contain an amino acid sequence that shares at least 60, 65, 70, 75, 80, 85, 90, 95, 97, 98 or 99 percent sequence identity with an amino acid sequence listed or otherwise disclosed herein. A particular variant amino acid sequence may comprise any number of variations as well as any combination of types of variations.
As indicated herein, polypeptides having a variant amino acid sequence can retain enzymatic activity. Such polypeptides can be produced by manipulating the nucleotide sequence encoding a polypeptide using standard procedures such as site-directed mutagenesis or various PCR techniques. As noted herein, one type of modification includes the substitution of one or more amino acid residues for amino acid residues having a similar chemical and/or biochemical property. For example, a polypeptide can have an amino acid sequence set forth in an amino acid sequence listed or otherwise disclosed herein comprising one or more conservative substitutions.
More substantial changes can be obtained by selecting substitutions that are less conservative, and/or in areas of the sequence that may be more critical, for example selecting residues that differ more significantly in their effect on maintaining: (a) the structure of the polypeptide backbone in the area of the substitution, for example, as a sheet or helical conformation; (b) the charge or hydrophobicity of the polypeptide at the target site; or (c) the bulk of the side chain. The substitutions that in general are expected to produce the greatest changes in polypeptide function are those in which: (a) a hydrophilic residue, e.g., serine or threonine, is substituted for (or by) a hydrophobic residue, e.g., leucine, isoleucine, phenylalanine, valine or alanine; (b) a cysteine or proline is substituted for (or by) any other residue; (c) a residue having an electropositive side chain, e.g., lysine, arginine, or histidine, is substituted for (or by) an electronegative residue, e.g., glutamic acid or aspartic acid; or (d) a residue having a bulky side chain, e.g., phenylalanine, is substituted for (or by) one not having a side chain, e.g., glycine. The effects of these amino acid substitutions (or other deletions or additions) can be assessed for polypeptides having enzymatic activity by analyzing the ability of the polypeptide to catalyze the conversion of the same substrate as the related native polypeptide to the same product as the related native polypeptide. Accordingly, polypeptides having 5, 10, 20, 30, 40, 50 or less conservative substitutions are provided by the invention.
As a practical matter, whether any particular polypeptide is at least 50%, 60%, 70%, 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to any reference amino acid sequence of any polypeptide described herein (which may correspond with a particular nucleic acid sequence described herein), such particular polypeptide sequence can be determined conventionally using known computer programs such the Bestfit program (Wisconsin Sequence Analysis Package, Version 8 for Unix, Genetics Computer Group, University Research Park, 575 Science Drive, Madison, Wis. 53711). When using Bestfit or any other sequence alignment program to determine whether a particular sequence is, for instance, 95% identical to a reference sequence according to the present invention, the parameters are set such that the percentage of identity is calculated over the full length of the reference amino acid sequence and that gaps in homology of up to 5% of the total number of amino acid residues in the reference sequence are allowed.
For example, in a specific embodiment the identity between a reference sequence (query sequence, i.e., a sequence of the present invention) and a subject sequence, also referred to as a global sequence alignment, may be determined using the FASTDB computer program based on the algorithm of Brutlag et al. (Comp. App. Biosci. 6:237-245 (1990)). Preferred parameters for a particular embodiment in which identity is narrowly construed, used in a FASTDB amino acid alignment, are: Scoring Scheme=PAM (Percent Accepted Mutations) 0, k-tuple=2, Mismatch Penalty=1, Joining Penalty=20, Randomization Group Length=0, Cutoff Score=1, Window Size=sequence length, Gap Penalty=5, Gap Size Penalty=0.05, Window Size=500 or the length of the subject amino acid sequence, whichever is shorter. According to this embodiment, if the subject sequence is shorter than the query sequence due to N- or C-terminal deletions, not because of internal deletions, a manual correction is made to the results to take into consideration the fact that the FASTDB program does not account for N- and C-terminal truncations of the subject sequence when calculating global percent identity. For subject sequences truncated at the N- and C-termini, relative to the query sequence, the percent identity is corrected by calculating the number of residues of the query sequence that are lateral to the N- and C-terminal of the subject sequence, which are not matched/aligned with a corresponding subject residue, as a percent of the total bases of the query sequence. A determination of whether a residue is matched/aligned is determined by results of the FASTDB sequence alignment. This percentage is then subtracted from the percent identity, calculated by the FASTDB program using the specified parameters, to arrive at a final percent identity score. This final percent identity score is what is used for the purposes of this embodiment. Only residues to the N- and C-termini of the subject sequence, which are not matched/aligned with the query sequence, are considered for the purposes of manually adjusting the percent identity score. That is, only query residue positions outside the farthest N- and C-terminal residues of the subject sequence are considered for this manual correction. For example, a 90 amino acid residue subject sequence is aligned with a 100 residue query sequence to determine percent identity. The deletion occurs at the N-terminus of the subject sequence and therefore, the FASTDB alignment does not show a matching/alignment of the first 10 residues at the N-terminus. The 10 unpaired residues represent 10% of the sequence (number of residues at the N- and C-termini not matched/total number of residues in the query sequence) so 10% is subtracted from the percent identity score calculated by the FASTDB program. If the remaining 90 residues were perfectly matched the final percent identity would be 90%. In another example, a 90 residue subject sequence is compared with a 100 residue query sequence. This time the deletions are internal deletions so there are no residues at the N- or C-termini of the subject sequence which are not matched/aligned with the query. In this case the percent identity calculated by FASTDB is not manually corrected. Once again, only residue positions outside the N- and C-terminal ends of the subject sequence, as displayed in the FASTDB alignment, which are not matched/aligned with the query sequence are manually corrected for.
Various methods and techniques may be used in accordance with the present invention to modify microorganisms. Embodiments of the present invention may result from introduction of an expression vector into a host microorganism, wherein the expression vector contains a nucleic acid sequence coding for an enzyme that is, or is not, normally found in a host microorganism.
The ability to genetically modify a host cell is essential for the production of any genetically modified (recombinant) microorganism. The mode of gene transfer technology may be by electroporation, conjugation, transduction, or natural transformation. A broad range of host conjugative plasmids and drug resistance markers are available. The cloning vectors are tailored to the host microorganisms based on the nature of antibiotic resistance markers that can function in that host. Also, as disclosed herein, a genetically modified (recombinant) microorganism may comprise modifications other than via plasmid introduction, including modifications to its genomic DNA.
More generally, nucleic acid constructs can be prepared comprising an isolated polynucleotide encoding a polypeptide having enzyme activity operably linked to one or more (several) control sequences that direct the expression of the coding sequence in a microorganism, such as E. coli, under conditions compatible with the control sequences. The isolated polynucleotide may be manipulated to provide for expression of the polypeptide. Manipulation of the polynucleotide's sequence prior to its insertion into a vector may be desirable or necessary depending on the expression vector. The techniques for modifying polynucleotide sequences utilizing recombinant DNA methods are well established in the art.
The control sequence may be an appropriate promoter sequence, a nucleotide sequence that is recognized by a host cell for expression of a polynucleotide encoding a polypeptide of the present invention. The promoter sequence contains transcriptional control sequences that mediate the expression of the polypeptide. The promoter may be any nucleotide sequence that shows transcriptional activity in the host cell of choice including mutant, truncated, and hybrid promoters, and may be obtained from genes encoding extracellular or intracellular polypeptides either homologous or heterologous to the host cell. Examples of suitable promoters for directing transcription of the nucleic acid constructs, especially in an E. coli host cell, are the lac promoter (Gronenborn, 1976, Mol. Gen. Genet. 148: 243-250), tac promoter (DeBoer et a/., 1983, Proceedings of the National Academy of Sciences USA 80: 21-25), trc promoter (Brosius et al, 1985, J. Biol. Chem. 260: 3539-3541), T7 RNA polymerase promoter (Studier and Moffatt, 1986, J. MoI. Biol. 189: 113-130), phage promoter pL (Elvin et al., 1990, Gene 87: 123-126), tetA promoter (Skerra, 1994, Gene 151: 131-135), araBAD promoter (Guzman et al., 1995, J. Bacteriol. 177: 4121-4130), and rhaPBAD promoter (Haldimann et al., 1998, J. Bacteriol. 180: 1277-1286). Other promoters are described in “Useful proteins from recombinant bacteria” in Scientific American, 1980, 242: 74-94; and in Sambrook and Russell, “Molecular Cloning: A Laboratory Manual,” Third Edition 2001 (volumes 1-3), Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.
The control sequence may also be a suitable transcription terminator sequence, a sequence recognized by a host cell to terminate transcription. The terminator sequence is operably linked to the 3′ terminus of the nucleotide sequence encoding the polypeptide. Any terminator that is functional in an E. coli cell may be used in the present invention. It may also be desirable to add regulatory sequences that allow regulation of the expression of the polypeptide relative to the growth of the host cell. Examples of regulatory systems are those that cause the expression of the gene to be turned on or off in response to a chemical or physical stimulus, including the presence of a regulatory compound. Regulatory systems in prokaryotic systems include the lac, tac, and trp operator systems.
For various embodiments of the invention the genetic manipulations and/or modifications may be described to include various genetic manipulations, including those directed to change regulation of, and therefore ultimate activity of, an enzyme or enzymatic activity of an enzyme identified in any of the respective pathways. Such genetic modifications, and any references herein to modulating a gene, may be directed to transcriptional, translational, and post-translational modifications that result in a change of enzyme activity and/or selectivity under selected and/or identified culture conditions and/or to provision of additional nucleic acid sequences such as to increase copy number and/or mutants of an enzyme related to fatty acid or fatty acid derived product production. Specific methodologies and approaches to achieve such genetic modification and/or modulation are well known to one skilled in the art, and include, but are not limited to: increasing expression of an endogenous genetic element; decreasing functionality of a repressor gene; introducing a heterologous genetic element; increasing copy number of a nucleic acid sequence encoding a polypeptide catalyzing an enzymatic conversion step to produce fatty acid or a fatty acid derived product; mutating a genetic element to provide a mutated protein to increase specific enzymatic activity; over-expressing; under-expressing; over-expressing a chaperone; knocking out a protease; altering or modifying feedback inhibition; providing an enzyme variant comprising one or more of an impaired binding site for a repressor and/or competitive inhibitor; knocking out a repressor gene; evolution, selection and/or other approaches to improve mRNA stability as well as use of plasmids having an effective copy number and promoters to achieve an effective level of improvement. Random mutagenesis may be practiced to provide genetic modifications that may fall into any of these or other stated approaches. The genetic modifications and/or modulation further broadly fall into additions (including insertions), deletions (such as by a mutation) and substitutions of one or more nucleic acids in a nucleic acid of interest. In various embodiments a genetic modification and/or modulation results in improved enzymatic specific activity and/or turnover number of an enzyme. Without being limited, changes may be measured by one or more of the following: KM; Kcat; and Kavidity.
In various embodiments, to function more efficiently, a microorganism may comprise one or more gene deletions. For example, in E. coli, the genes encoding the lactate dehydrogenase (ldhA), phosphate acetyltransferase (pta), pyruvate oxidase (poxB), and pyruvate-formate lyase (pflB) may be disrupted, including deleted. Such gene disruptions, including deletions, are not meant to be limiting, and may be implemented in various combinations in various embodiments. Gene deletions may be accomplished by mutational gene deletion approaches, and/or starting with a mutant strain having reduced or no expression of one or more of these enzymes, and/or other methods known to those skilled in the art. Gene deletions may be effectuated by any of a number of known specific methodologies, including but not limited to the RED/ET methods using kits and other reagents sold by Gene Bridges (Gene Bridges GmbH, Dresden, Germany, <<www.genebridges.com>>).
More particularly as to the latter method, use of Red/ET recombination, is known to those of ordinary skill in the art and described in U.S. Pat. Nos. 6,355,412 and 6,509,156, issued to Stewart et al. and incorporated by reference herein for its teachings of this method. Material and kits for such method are available from Gene Bridges (Gene Bridges GmbH, Dresden, Germany, <<www.genebridges.com>>), and the method may proceed by following the manufacturer's instructions. The method involves replacement of the target gene by a selectable marker via homologous recombination performed by the recombinase from λ-phage. The host microorganism expressing λ-red recombinase is transformed with a linear DNA product coding for a selectable marker flanked by the terminal regions (generally ˜50 bp, and alternatively up to about ˜300 bp) homologous with the target gene. The marker could then be removed by another recombination step performed by a plasmid vector carrying the FLP-recombinase, or another recombinase, such as Cre.
Targeted deletion of parts of microbial chromosomal DNA or the addition of foreign genetic material to microbial chromosomes may be practiced to alter a host cell's metabolism so as to reduce or eliminate production of undesired metabolic products. This may be used in combination with other genetic modifications such as described herein in this general example. In this detailed description, reference has been made to multiple embodiments and to the accompanying drawings in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that modifications to the various disclosed embodiments may be made by a skilled artisan.
Polypeptides and nucleic acids encoding polypeptides can be produced by standard DNA mutagenesis techniques, for example, M13 primer mutagenesis. Details of these techniques are provided in Sambrook and Russell, 2001. Nucleic acid molecules can contain changes of a coding region to fit the codon usage bias of the particular microorganism into which the molecule is to be introduced.
Alternatively, the coding region can be altered by taking advantage of the degeneracy of the genetic code to alter the coding sequence in such a way that, while the nucleic acid sequence is substantially altered, it nevertheless encodes a polypeptide having an amino acid sequence identical or substantially similar to the native amino acid sequence. For example, alanine is encoded in the open reading frame by the nucleotide codon triplet GCT. Because of the degeneracy of the genetic code, three other nucleotide codon triplets—GCA, GCC, and GCG—also code for alanine Thus, the nucleic acid sequence of the open reading frame can be changed at this position to any of these three codons without affecting the amino acid sequence of the encoded polypeptide or the characteristics of the polypeptide. Based upon the degeneracy of the genetic code, nucleic acid variants can be derived from a nucleic acid sequence disclosed herein using standard DNA mutagenesis techniques as described herein, or by synthesis of nucleic acid sequences. Thus, for various embodiments the invention encompasses nucleic acid molecules that encode the same polypeptide but vary in nucleic acid sequence by virtue of the degeneracy of the genetic code.
The invention also provides an isolated nucleic acid that is at least about 12 bases in length (e.g., at least about 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 40, 50, 60, 100, 250, 500, 750, 1000, 1500, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 19000 or 20000 bases in length) and hybridizes, under hybridization conditions, to the sense or antisense strand of a nucleic acid having a sequence listed or otherwise disclosed herein. The hybridization conditions can be moderately or highly stringent hybridization conditions.
In accordance with the present invention, the microorganisms described herein are used in a fermentation process to produce a desired chemical product, such as a fatty acid or fatty acid derivative, through the bioproduction pathways described herein. Without being limiting, such a process may be exemplified by providing into a vessel, such as a culture or bioreactor vessel, the following: (1) bio-production media, (2) nutrient media, such as a minimal media as known to those skilled in the art, and (3) an inoculum of a genetically modified microorganism so as to provide a population of such microorganism, such as a bacterium, and more particularly a member of the family Enterobacteriaceae, such as E. coli. In accordance with one aspect of the invention, the genetically modified microorganism comprises a metabolic pathway that converts malonyl-CoA to a selected chemical product. The inoculum is cultured in the vessel so that the cell density increases to a cell density suitable for reaching a production level of a fatty acid or fatty acid derived product that meets the desired overall productivity metrics. In various alternative embodiments, a population of these genetically modified microorganisms may be cultured to a first cell density in a first, preparatory vessel, and then transferred to the noted vessel so as to provide the selected cell density. Numerous multi-vessel culturing strategies are known to those skilled in the art.
Bio-production media, which is used in the present invention with recombinant microorganisms having a biosynthetic pathway for a fatty acid or fatty acid derived product, may contain suitable carbon sources or substrates for the intended metabolic pathways. Suitable substrates may include, but are not limited to, monosaccharides such as glucose and fructose, oligosaccharides such as lactose or sucrose, polysaccharides such as starch or cellulose or mixtures thereof and unpurified mixtures from renewable feedstocks such as cheese whey permeate, cornsteep liquor, sugar beet molasses, and barley malt. Additionally the carbon substrate may also be one-carbon substrates such as carbon dioxide, carbon monoxide, or methanol for which metabolic conversion into key biochemical intermediates has been demonstrated. In addition to one and two carbon substrates methylotrophicmicroorganisms are also known to utilize a number of other carbon containing compounds such as methylamine, glucosamine and a variety of amino acids for metabolic activity.
Although it is contemplated that all of the above mentioned carbon substrates and mixtures thereof are suitable in the present invention as a carbon source, common carbon substrates used as carbon sources are various monomeric and oligomeric sugars, such as for example glucose, fructose, and sucrose, as well as mixtures of any of these sugars. Other suitable substrates include xylose, arabinose, other cellulose-based C-5 sugars, high-fructose corn syrup, and various other sugars and sugar mixtures as are available commercially. Sucrose may be obtained from feedstocks such as sugar cane, sugar beets, cassava, bananas or other fruit, and sweet sorghum. Glucose and dextrose may be obtained through saccharification of starch based feedstocks including grains such as corn, wheat, rye, barley, and oats. Also, in some embodiments all or a portion of the carbon source may be glycerol. Alternatively, glycerol may be excluded as an added carbon source.
In one embodiment, the carbon source is selected from glucose, fructose, sucrose, dextrose, lactose, glycerol, and mixtures thereof. Variously and independently, the amount of these components in the carbon source may be greater than about 50%, greater than about 60%, greater than about 70%, greater than about 80%, greater than about 90%, or more, up to 100% or essentially 100% of the carbon source.
In addition, methylotrophicmicroorganisms are known to utilize a number of other carbon containing compounds such as methylamine, glucosamine and a variety of amino acids for metabolic activity. For example, methylotrophic yeast are known to utilize the carbon from methylamine to form trehalose or glycerol (Bellion et al., Microb. Growth C1 Compd. (Int. Symp.), 7th (1993), 415-32. Editor(s): Murrell, J. Collin; Kelly, Don P. Publisher: Intercept, Andover, UK). Similarly, various species of Candida will metabolize alanine or oleic acid (Sulter et al., Arch. Microbiol. 153:485-489 (1990)). Hence it is contemplated that the source of carbon utilized in embodiments of the present invention may encompass a wide variety of carbon-containing substrates.
In addition, fermentable sugars may be obtained from cellulosic and lignocellulosic biomass through processes of pretreatment and saccharification, as described, for example, in U.S. Patent Publication No. 2007/0031918A1, which is herein incorporated by reference. Biomass refers to any cellulosic or lignocellulosic material and includes materials comprising cellulose, and optionally further comprising hemicellulose, lignin, starch, oligosaccharides and/or monosaccharides. Biomass may also comprise additional components, such as protein and/or lipid. Biomass may be derived from a single source, or biomass can comprise a mixture derived from more than one source; for example, biomass could comprise a mixture of corn cobs and corn stover, or a mixture of grass and leaves. Biomass includes, but is not limited to, bioenergy crops, agricultural residues, municipal solid waste, industrial solid waste, sludge from paper manufacture, yard waste, wood and forestry waste. Examples of biomass include, but are not limited to, corn grain, corn cobs, crop residues such as corn husks, corn stover, grasses, wheat, wheat straw, barley, barley straw, hay, rice straw, switchgrass, waste paper, sugar cane bagasse, sorghum, soy, components obtained from milling of grains, trees, branches, roots, leaves, wood chips, sawdust, shrubs and bushes, vegetables, fruits, flowers and animal manure. Any such biomass may be used in a bio-production method or system to provide a carbon source. Various approaches to breaking down cellulosic biomass to mixtures of more available and utilizable carbon molecules, including sugars, include: heating in the presence of concentrated or dilute acid (e.g., <1% sulfuric acid); treating with ammonia; treatment with ionic salts; enzymatic degradation; and combinations of these. These methods normally follow mechanical separation and milling, and are followed by appropriate separation processes.
In various embodiments, any of a wide range of sugars, including, but not limited to sucrose, glucose, xylose, cellulose or hemicellulose, are provided to a microorganism, such as in an industrial system comprising a reactor vessel in which a defined media (such as a minimal salts media including but not limited to M9 minimal media, potassium sulfate minimal media, yeast synthetic minimal media and many others or variations of these), an inoculum of a microorganism providing one or more of the fatty acid or fatty acid derived biosynthetic pathway alternatives, and the a carbon source may be combined. The carbon source enters the cell and is catabolized by well-known and common metabolic pathways to yield common metabolic intermediates, including phosphoenolpyruvate (PEP). (See Molecular Biology of the Cell, 3rd Ed., B. Alberts et al. Garland Publishing, New York, 1994, pp. 42-45, 66-74, incorporated by reference for the teachings of basic metabolic catabolic pathways for sugars; Principles of Biochemistry, 3rd Ed., D. L. Nelson & M. M. Cox, Worth Publishers, New York, 2000, pp 527-658, incorporated by reference for the teachings of major metabolic pathways; and Biochemistry, 4th Ed., L. Stryer, W. H. Freeman and Co., New York, 1995, pp. 463-650, also incorporated by reference for the teachings of major metabolic pathways.)
Bio-based carbon can be distinguished from petroleum-based carbon according to a variety of methods, including without limitation ASTM D6866, or various other techniques. For example, carbon-14 and carbon-12 ratios differ in bio-based carbon sources versus petroleum-based sources, where higher carbon-14 ratios are found in bio-based carbon sources. In various embodiments, the carbon source is not petroleum-based, or is not predominantly petroleum based. In various embodiments, the carbon source is greater than about 50% non-petroleum based, greater than about 60% non-petroleum based, greater than about 70% non-petroleum based, greater than about 80% non-petroleum based, greater than about 90% non-petroleum based, or more. In various embodiments, the carbon source has a carbon-14 to carbon-12 ratio of about 1.0×10-14 or greater, for example, 2.0×10-14 or greater, 3.0×10-14 or greater, 4.0×10-14 or greater, 5.0×10-14 or greater, 6.0×10-14 or greater, 7.0×10-14 or greater, 8.0×10-14 or greater, 9.0×10-14 or greater, or 10.0×10-14 or greater.
The carbon source of any embodiment, comprising a C6 carbon source or C3 carbon source. The carbon source of any embodiment, comprising one or more cellulosic sugars, such as glucose, sucrose, fructose, dextrose, lactose, xylose, or any combination thereof. The carbon source of any embodiment, comprising less than about 50%, 40%, 30%, 20%, 10%, or 5% by mass of glycerol.
The fermentation bioproduction process in accordance with the present invention may utilize an inoculum comprising any of the genetically modified microorganism described hereinabove. Features as described and claimed herein may be provided in a microorganism selected from the listing herein, or another suitable microorganism, that also comprises one or more natural, introduced, or enhanced fatty acid or fatty acid derived product bio-production pathways. Thus, in some embodiments the microorganism comprises an endogenous fatty acid or fatty acid derived product production pathway (which may, in some such embodiments, be enhanced), whereas in other embodiments the microorganism does not comprise an endogenous fatty acid or fatty acid derived product production pathway.
Varieties of these genetically modified microorganisms may comprise genetic modifications and/or other system alterations as may be described in other patent applications of one or more of the present inventor(s) and/or subject to assignment to the owner of the present patent application.
The examples describe specific modifications and evaluations to certain bacterial and yeast microorganisms. The scope of the invention is not meant to be limited to such species, but to be generally applicable to a wide range of suitable microorganisms. Generally, a microorganism used for the present invention may be selected from bacteria, cyanobacteria, filamentous fungi and yeasts.
For some embodiments, microbial hosts initially selected for bio-production of a selected chemical product should also utilize sugars including glucose at a high rate. Most microbes are capable of utilizing carbohydrates. However, certain environmental microbes cannot utilize carbohydrates to high efficiency, and therefore would not be suitable hosts for such embodiments that are intended for glucose or other carbohydrates as the principal added carbon source.
As the genomes of various species become known, the present invention easily may be applied to an ever-increasing range of suitable microorganisms. Further, given the relatively low cost of genetic sequencing, the genetic sequence of a species of interest may readily be determined to make application of aspects of the present invention more readily obtainable (based on the ease of application of genetic modifications to a microorganism having a known genomic sequence).
More particularly, based on the various criteria described herein, suitable microbial hosts for the bio-production of a chemical product generally may include, but are not limited to, any gram negative microorganisms, more particularly a member of the family Enterobacteriaceae, such as E. coli, or Oligotropha carboxidovorans, or Pseudomononas sp.; any gram positive microorganism, for example Bacillus subtilis, Lactobaccilus sp. or Lactococcus sp.; a yeast, for example Saccharomyces cerevisiae, Pichia pastoris or Pichia stipitis; and other groups or microbial species. More particularly, suitable microbial hosts for the bio-production of a fatty acid or fatty acid derived product generally include, but are not limited to, members of the genera Clostridium, Zymomonas, Escherichia, Salmonella, Rhodococcus, Pseudomonas, Bacillus, Lactobacillus, Enterococcus, Alcaligenes, Klebsiella, Paenibacillus, Arthrobacter, Corynebacterium, Brevibacterium, Pichia, Candida, Hansenula and Saccharomyces. Hosts that may be particularly of interest include: Oligotropha carboxidovorans (such as strain OM5), Escherichia coli, Alcaligenes eutrophus (Cupriavidus necator), Bacillus licheniformis, Paenibacillus macerans, Rhodococcus erythropolis, Pseudomonas putida, Lactobacillus plantarum, Enterococcus faecium, Enterococcus gallinarium, Enterococcus faecalis, Bacillus subtilis and Saccharomyces cerevisiae.
More particularly, suitable microbial hosts for the bio-production of fatty acid or fatty acid derived product generally include, but are not limited to, members of the genera Clostridium, Zymomonas, Escherichia, Salmonella, Rhodococcus, Pseudomonas, Bacillus, Lactobacillus, Enterococcus, Alcaligenes, Klebsiella, Paenibacillus, Arthrobacter, Corynebacterium, Brevibacterium, Pichia, Candida, Hansenula and Saccharomyces.
Hosts that may be particularly of interest include: Oligotropha carboxidovorans (such as strain OM5T), Escherichia coli, Alcaligenes eutrophus (Cupriavidus necator), Bacillus licheniformis, Paenibacillus macerans, Rhodococcus erythropolis, Pseudomonas putida, Lactobacillus plantarum, Enterococcus faecium, Enterococcus gallinarium, Enterococcus faecalis, Bacillus subtilis and Saccharomyces cerevisiae. Also, any of the known strains of these species may be utilized as a starting microorganism, as may any of the following species including respective strains thereof—Cupriavidus basilensis, Cupriavidus campinensis, Cupriavidus gilardi, Cupriavidus laharsis, Cupriavidus metallidurans, Cupriavidus oxalaticus, Cupriavidus pauculus, Cupriavidus pinatubonensis, Cupriavidus respiraculi, and Cupriavidus taiwanensis.
In some embodiments, the recombinant microorganism is a gram-negative bacterium. In some embodiments, the recombinant microorganism is selected from the genera Zymomonas, Escherichia, Pseudomonas, Alcaligenes, and Klebsiella. In some embodiments, the recombinant microorganism is selected from the species Escherichia coli, Cupriavidus necator, Oligotropha carboxidovorans, and Pseudomonas putida. In some embodiments, the recombinant microorganism is an E. coli strain.
In some embodiments, the recombinant microorganism is a gram-positive bacterium. In some embodiments, the recombinant microorganism is selected from the genera Clostridium, Salmonella, Rhodococcus, Bacillus, Lactobacillus, Enterococcus, Paenibacillus, Arthrobacter, Corynebacterium, and Brevibacterium. In some embodiments, the recombinant microorganism is selected from the species Bacillus licheniformis, Paenibacillus macerans, Rhodococcus erythropolis, Lactobacillus plantarum, Enterococcus faecium, Enterococcus gallinarium, Enterococcus faecalis, and Bacillus subtilis. In particular embodiments, the recombinant microorganism is a B. subtilis strain.
In some embodiments, the recombinant microorganism is yeast. In some embodiments, the recombinant microorganism is selected from the genera Pichia, Candida, Hansenula, Klebsiella, Issatchenkia, and Saccharomyces. In particular embodiments, the recombinant microorganism is Saccharomyces cerevisiae.
It is further appreciated, in view of the disclosure, that any of the above microorganisms may be used for production of chemical products other than fatty acid or fatty acid derived product.
The ability to genetically modify the host is essential for the production of any recombinant microorganism. The mode of gene transfer technology may be by electroporation, conjugation, transduction or natural transformation. A broad range of host conjugative plasmids and drug resistance markers are available. The cloning vectors are tailored to the host microorganisms based on the nature of antibiotic resistance markers that can function in that host.
In addition to an appropriate carbon source, such as selected from one of the herein-disclosed types, bio-production media must contain suitable minerals, salts, cofactors, buffers and other components, known to those skilled in the art, suitable for the growth of the cultures and promotion of the enzymatic pathway necessary for chemical product bio-production under the present invention.
Another aspect of the invention regards media and culture conditions that comprise genetically modified microorganisms of the invention and optionally supplements.
Typically cells are grown at a temperature in the range of about 25° C. to about 40° C. in an appropriate medium, as well as up to 70° C. for thermophilic microorganisms. Suitable growth media in the present invention are common commercially prepared media such as Luria Bertani (LB) broth, Terrific Broth (TB), M9 minimal media, Sabouraud Dextrose (SD) broth, Yeast medium (YM) broth, (Ymin) yeast synthetic minimal media, and minimal media as described herein, such as M9 minimal media. Other defined or synthetic growth media may also be used, and the appropriate medium for growth of the particular microorganism will be known by one skilled in the art of microbiology or bio-production science. In various embodiments a minimal media may be developed and used that does not comprise, or that has a low level of addition of various components, for example less than 10, 5, 2 or 1 g/L of a complex nitrogen source including but not limited to yeast extract, peptone, tryptone, soy flour, corn steep liquor, or casein. These minimal medias may also have limited supplementation of vitamin mixtures including biotin, vitamin B12 and derivatives of vitamin B12, thiamin, pantothenate and other vitamins. Minimal media may also have limited simple inorganic nutrient sources containing less than 28, 17, or 2.5 mM phosphate, less than 25 or 4 mM sulfate, and less than 130 or 50 mM total nitrogen.
Suitable pH ranges for the bio-production are from pH 3.0 to pH 10.0, where pH 6.0 to pH 8.0 is a typical pH range for the initial condition. For example, the pH can be 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, or 10.0 However, the actual culture conditions for a particular embodiment are not meant to be limited by these pH ranges.
Bio-productions may be performed under aerobic, microaerobic, or anaerobic conditions, with or without agitation.
In various embodiments, specific supplements to a bioreactor vessel comprising such microorganism population may also be provided to further improve the methods and systems.
Fermentation systems utilizing methods and/or compositions according to the invention are also within the scope of the invention.
Any of the recombinant microorganisms as described and/or referred to herein may be introduced into an industrial bio-production system where the microorganisms convert a carbon source into a fatty acid or fatty acid derived product in a commercially viable operation. The bio-production system includes the introduction of such a recombinant microorganism into a bioreactor vessel, with a carbon source substrate and bio-production media suitable for growing the recombinant microorganism, and maintaining the bio-production system within a suitable temperature range (and dissolved oxygen concentration range if the reaction is aerobic or microaerobic) for a suitable time to obtain a desired conversion of a portion of the substrate molecules to a selected chemical product. Industrial bio-production systems and their operation are well-known to those skilled in the arts of chemical engineering and bioprocess engineering.
Bio-productions may be performed under aerobic, microaerobic, or anaerobic conditions, with or without agitation. The operation of cultures and populations of microorganisms to achieve aerobic, microaerobic and anaerobic conditions are known in the art, and dissolved oxygen levels of a liquid culture comprising a nutrient media and such microorganism populations may be monitored to maintain or confirm a desired aerobic, microaerobic or anaerobic condition. When syngas is used as a feedstock, aerobic, microaerobic, or anaerobic conditions may be utilized. When sugars are used, anaerobic, aerobic or microaerobic conditions can be implemented in various embodiments.
Any of the recombinant microorganisms as described and/or referred to herein may be introduced into an industrial bio-production system where the microorganisms convert a carbon source into a selected chemical product in a commercially viable operation. The bio-production system includes the introduction of such a recombinant microorganism into a bioreactor vessel, with a carbon source substrate and bio-production media suitable for growing the recombinant microorganism, and maintaining the bio-production system within a suitable temperature range (and dissolved oxygen concentration range if the reaction is aerobic or microaerobic) for a suitable time to obtain a desired conversion of a portion of the substrate molecules to the selected chemical product.
In various embodiments, syngas components or sugars are provided to a microorganism, such as in an industrial system comprising a reactor vessel in which a defined media (such as a minimal salts media including but not limited to M9 minimal media, potassium sulfate minimal media, yeast synthetic minimal media and many others or variations of these), an inoculum of a microorganism providing an embodiment of the biosynthetic pathway(s) taught herein, and the carbon source may be combined. The carbon source enters the cell and is catabolized by well-known and common metabolic pathways to yield common metabolic intermediates, including phosphoenolpyruvate (PEP) or acetyl-CoA. (See Molecular Biology of the Cell, 3rd Ed., B. Alberts et al. Garland Publishing, New York, 1994, pp. 42-45, 66-74, incorporated by reference for the teachings of basic metabolic catabolic pathways for sugars; Principles of Biochemistry, 3rd Ed., D. L. Nelson & M. M. Cox, Worth Publishers, New York, 2000, pp. 527-658, incorporated by reference for the teachings of major metabolic pathways; and Biochemistry, 4th Ed., L. Stryer, W. H. Freeman and Co., New York, 1995, pp. 463-650, also incorporated by reference for the teachings of major metabolic pathways).
Further to types of industrial bio-production, various embodiments of the present invention may employ a batch type of industrial bioreactor. A classical batch bioreactor system is considered “closed” meaning that the composition of the medium is established at the beginning of a respective bio-production event and not subject to artificial alterations and additions during the time period ending substantially with the end of the bio-production event. Thus, at the beginning of the bio-production event the medium is inoculated with the desired microorganism or microorganisms, and bio-production is permitted to occur without adding anything to the system. Typically, however, a “batch” type of bio-production event is batch with respect to the addition of carbon source and attempts are often made at controlling factors such as pH and oxygen concentration. In batch systems the metabolite and biomass compositions of the system change constantly up to the time the bio-production event is stopped. Within batch cultures cells moderate through a static lag phase to a high growth log phase and finally to a stationary phase where growth rate is diminished or halted. If untreated, cells in the stationary phase will eventually die. Cells in log phase generally are responsible for the bulk of production of a desired end product or intermediate.
A variation on the standard batch system is the fed-batch system. Fed-batch bio-production processes are also suitable in the present invention and comprise a typical batch system with the exception that the nutrients, including the substrate, are added in increments as the bio-production progresses. Fed-Batch systems are useful when catabolite repression is apt to inhibit the metabolism of the cells and where it is desirable to have limited amounts of substrate in the media. Measurement of the actual nutrient concentration in Fed-Batch systems may be measured directly, such as by sample analysis at different times, or estimated on the basis of the changes of measurable factors such as pH, dissolved oxygen and the partial pressure of waste gases such as CO2. Batch and fed-batch approaches are common and well known in the art and examples may be found in Thomas D. Brock in Biotechnology: A Textbook of Industrial Microbiology, Second Edition (1989) Sinauer Associates, Inc., Sunderland, Mass., Deshpande, Mukund V., Appl. Biochem. Biotechnol., 36:227, (1992), and Biochemical Engineering Fundamentals, 2nd Ed. J. E. Bailey and D. F. Ollis, McGraw Hill, New York, 1986, herein incorporated by reference for general instruction on bio-production.
Although embodiments of the present invention may be performed in batch mode, or in fed-batch mode, it is contemplated that the invention would be adaptable to continuous bio-production methods. Continuous bio-production is considered an “open” system where a defined bio-production medium is added continuously to a bioreactor and an equal amount of conditioned media is removed simultaneously for processing. Continuous bio-production generally maintains the cultures within a controlled density range where cells are primarily in log phase growth. Two types of continuous bioreactor operation include a chemostat, wherein fresh media is fed to the vessel while simultaneously removing an equal rate of the vessel contents. The limitation of this approach is that cells are lost and high cell density generally is not achievable. In fact, typically one can obtain much higher cell density with a fed-batch process. Another continuous bioreactor utilizes perfusion culture, which is similar to the chemostat approach except that the stream that is removed from the vessel is subjected to a separation technique which recycles viable cells back to the vessel. This type of continuous bioreactor operation has been shown to yield significantly higher cell densities than fed-batch and can be operated continuously. Continuous bio-production is particularly advantageous for industrial operations because it has less down time associated with draining, cleaning and preparing the equipment for the next bio-production event. Furthermore, it is typically more economical to continuously operate downstream unit operations, such as distillation, than to run them in batch mode.
Continuous bio-production allows for the modulation of one factor or any number of factors that affect cell growth or end product concentration. For example, one method will maintain a limiting nutrient such as the carbon source or nitrogen level at a fixed rate and allow all other parameters to moderate. In other systems a number of factors affecting growth can be altered continuously while the cell concentration, measured by media turbidity, is kept constant. Methods of modulating nutrients and growth factors for continuous bio-production processes as well as techniques for maximizing the rate of product formation are well known in the art of industrial microbiology and a variety of methods are detailed by Brock, supra.
It is contemplated that embodiments of the present invention may be practiced using either batch, fed-batch or continuous processes and that any known mode of bio-production would be suitable. It is contemplated that cells may be immobilized on an inert scaffold as whole cell catalysts and subjected to suitable bio-production conditions for chemical product bio-production, or be cultured in liquid media in a vessel, such as a culture vessel. Thus, embodiments used in such processes, and in bio-production systems using these processes, include a population of genetically modified microorganisms of the present invention, a culture system comprising such population in a media comprising nutrients for the population, and methods of making a selected chemical product.
Embodiments of the invention include methods of making a selected chemical product in a bio-production system, some of which methods may include obtaining a fatty acid or fatty acid derived product after such bio-production event. For example, a method of making a fatty acid or fatty acid derived product may comprise: providing to a culture vessel a media comprising suitable nutrients; providing to the culture vessel an inoculum of a genetically modified microorganism comprising genetic modifications described herein such that the microorganism produces a selected chemical product from syngas and/or a sugar molecule; and maintaining the culture vessel under suitable conditions for the genetically modified microorganism to produce a selected chemical product.
It is within the scope of the present invention to produce, and to utilize in bio-production methods and systems, including industrial bio-production systems for production of a selected chemical product, a recombinant microorganism genetically engineered to modify one or more aspects effective to increase chemical product bio-production by at least 20 percent over control microorganism lacking the one or more modifications.
In various embodiments, the invention is directed to a system for bio-production of a chemical product as described herein, said system comprising: a fermentation tank suitable for microorganism cell culture; a line for discharging contents from the fermentation tank to an extraction and/or separation vessel; and an extraction and/or separation vessel suitable for removal of the chemical product from cell culture waste. In various embodiments, the system includes one or more pre-fermentation tanks, distillation columns, centrifuge vessels, back extraction columns, mixing vessels, or combinations thereof.
The following published resources are incorporated by reference herein for their respective teachings to indicate the level of skill in these relevant arts, and as needed to support a disclosure that teaches how to make and use methods of industrial bio-production of chemical product(s) produced under the invention, from sugar sources, and also industrial systems that may be used to achieve such conversion with any of the recombinant microorganisms of the present invention (Biochemical Engineering Fundamentals, 2nd Ed. J. E. Bailey and D. F. Ollis, McGraw Hill, New York, 1986, entire book for purposes indicated and Chapter 9, pages 533-657 in particular for biological reactor design; Unit Operations of Chemical Engineering, 5th Ed., W. L. McCabe et al., McGraw Hill, New York 1993, entire book for purposes indicated, and particularly for process and separation technologies analyses; Equilibrium Staged Separations, P. C. Wankat, Prentice Hall, Englewood Cliffs, N.J. USA, 1988, entire book for separation technologies teachings).
In some embodiments, the genetic modification increases microbial synthesis of a selected fatty acid or fatty acid derived chemical product above a rate or titer of a control microorganism lacking said at least one genetic modification to produce a selected chemical product. In some embodiments, the genetic modification is effective to increase enzymatic conversions to a selected chemical product by at least about 5 percent, at least about 10 percent, at least about 20 percent, at least about 30 percent, or at least about 50 percent above the enzymatic conversion of a control microorganism lacking the genetic modification. In various embodiments, bio-production of a selected chemical product may reach at least 1, at least 2, at least 5, at least 10, at least 20, at least 30, at least 40, and at least 50 g/liter titer, such as by using one of the methods disclosed herein.
As may be realized by appreciation of the advances disclosed herein as they relate to commercial fermentations of selected chemical products, embodiments of the present invention may be combined with other genetic modifications and/or method or system modulations so as to obtain a microorganism (and corresponding method) effective to produce at least 10, at least 20, at least 30, at least 40, at least 45, at least 50, at least 80, at least 100, or at least 120 grams of a chemical product (such as a fatty acid or fatty acid derivative) per liter of final (e.g., spent) fermentation broth while achieving this with specific and/or volumetric productivity rates as disclosed herein. The amount of a chemical product produced in a bio-production media generally can be determined using a number of methods known in the art, for example, high performance liquid chromatography (HPLC), gas chromatography (GC), or GC/Mass Spectroscopy (MS).
Unexpected increases in specific productivity by a population of a genetically modified microorganism may be achieved in methods and systems in which that microorganism has a microbial production pathway from malonyl-CoA to a selected chemical product as well as a reduction in the enzymatic activity of a selected enzyme of the microorganism's fatty acid synthase system (more particularly, its malonyl-ACP dependent fatty acid elongation enzymes), in addition to the increase activity of a microorganisms malonyl-CoA dependent fatty acyl-CoA production pathway.
In some embodiments a microbial chemical bio-production event (i.e., a fermentation event using a cultured population of a microorganism) proceeds using a genetically modified microorganism as described herein, wherein the specific productivity is between 0.01 and 0.60 grams of selected chemical product produced per gram of microorganism cell on a dry weight basis per hour (g chemical product/g DCW-hr). In various embodiments the specific productivity is greater than 0.01, greater than 0.05, greater than 0.10, greater than 0.15, greater than 0.20, greater than 0.25, greater than 0.30, greater than 0.35, greater than 0.40, greater than 0.45, or greater than 0.50 g chemical product/g DCW-hr. Specific productivity may be assessed over a 2, 4, 6, 8, 12 or 24 hour period in a particular microbial chemical production event. More particularly, the specific productivity for a chemical product is between 0.05 and 0.10, 0.10 and 0.15, 0.15 and 0.20, 0.20 and 0.25, 0.25 and 0.30, 0.30 and 0.35, 0.35 and 0.40, 0.40 and 0.45, or 0.45 and 0.50 g chemical product/g DCW-hr., 0.50 and 0.55, or 0.55 and 0.60 g chemical product/g DCW-hr. Various embodiments comprise culture systems demonstrating such productivity.
Also, in various embodiments of the present invention the volumetric productivity achieved may be about 0.25 g fatty acid (or other chemical product) per liter per hour (g (chemical product)/L-hr), may be greater than about 0.25 g fatty acid (or other chemical product)/L-hr, may be greater than about 0.50 g fatty acid (or other chemical product)/L-hr, may be greater than about 1.0 g fatty acid (or other chemical product)/L-hr, may be greater than about 1.50 g fatty acid (or other chemical product)/L-hr, may be greater than about 2.0 g fatty acid (or other chemical product)/L-hr, may be greater than about 2.50 g fatty acid (or other chemical product)/L-hr, may be greater than about 3.0 g fatty acid (or other chemical product)/L-hr, may be greater than about 3.50 g fatty acid (or other chemical product)/L-hr, may be greater than about 4.0 g fatty acid (or other chemical product)/L-hr, may be greater than about 4.50 g fatty acid (or other chemical product)/L-hr, may be greater than about 5.0 g fatty acid (or other chemical product)/L-hr, may be greater than about 5.50 g fatty acid (or other chemical product)/L-hr, may be greater than about 6.0 g fatty acid (or other chemical product)/L-hr, may be greater than about 6.50 g fatty acid (or other chemical product)/L-hr, may be greater than about 7.0 g fatty acid (or other chemical product)/L-hr, may be greater than about 7.50 g fatty acid (or other chemical product)/L-hr, may be greater than about 8.0 g fatty acid (or other chemical product)/L-hr, may be greater than about 8.50 g fatty acid (or other chemical product)/L-hr, may be greater than about 9.0 g fatty acid (or other chemical product)/L-hr, may be greater than about 9.50 g fatty acid (or other chemical product)/L-hr, or may be greater than about 10.0 g fatty acid (or other chemical product)/L-hr.
In some embodiments, specific productivity as measured over a 24-hour fermentation (culture) period may be greater than about 0.01, 0.05, 0.10, 0.20, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0 or 12.0 grams of chemical product per gram DCW of microorganisms (based on the final DCW at the end of the 24-hour period).
In various aspects and embodiments of the present invention, there is a resulting substantial increase in microorganism specific productivity that advances the fermentation art and commercial economic feasibility of microbial chemical production, such as of a fatty acid (but not limited thereto).
Stated in another manner, in various embodiments the specific productivity exceeds (is at least) 0.01 g chemical product/g DCW-hr, exceeds (is at least) 0.05 g chemical product/g DCW-hr, exceeds (is at least) 0.10 g chemical product/g DCW-hr, exceeds (is at least) 0.15 g chemical product/g DCW-hr, exceeds (is at least) 0.20 g chemical product/g DCW-hr, exceeds (is at least) 0.25 g chemical product/g DCW-hr, exceeds (is at least) 0.30 g chemical product/g DCW-hr, exceeds (is at least) 0.35 g chemical product/g DCW-hr, exceeds (is at least) 0.40 g chemical product/g DCW-hr, exceeds (is at least) 0.45 g chemical product/g DCW-hr, exceeds (is at least) 0.50 g chemical product/g DCW-hr, exceeds (is at least) 0.60 g chemical product/g DCW-hr. In accordance with certain embodiments of the present invention the chemical product is a fatty acid or a fatty acid derived product.
More generally, based on various combinations of the genetic modifications described herein, optionally in combination with supplementations described herein, specific productivity values for a fatty acid or fatty acid derived product, and for other chemical products described herein, may exceed 0.01 g chemical product/g DCW-hr, may exceed 0.05 g chemical product/g DCW-hr, may exceed 0.10 g chemical product/g DCW-hr, may exceed 0.15 g chemical product/g DCW-hr, may exceed 0.20 g chemical product/g DCW-hr, may exceed 0.25 g chemical product/g DCW-hr, may exceed 0.30 g chemical product/g DCW-hr, may exceed 0.35 g chemical product/g DCW-hr, may exceed 0.40 g chemical product/g DCW-hr, may exceed 0.45 g chemical product/g DCW-hr, and may exceed 0.50 g or 0.60 chemical product/g DCW-hr. Such specific productivity may be assessed over a 2, 4, 6, 8, 12 or 24 hour period in a particular microbial chemical production event.
The improvements achieved by embodiments of the present invention may be determined by percentage increase in specific productivity, or by percentage increase in volumetric productivity, compared with an appropriate control microorganism lacking the particular genetic modification combinations taught herein (with or without the supplements taught herein, added to a vessel comprising the microorganism population). For particular embodiments and groups thereof, such specific productivity and/or volumetric productivity improvements is/are at least 10, at least 20, at least 30, at least 40, at least 50, at least 100, at least 200, at least 300, at least 400, and at least 500 percent over the respective specific productivity and/or volumetric productivity of such appropriate control microorganism.
The specific methods and teachings of the specification, and/or cited references that are incorporated by reference, may be incorporated into the examples. Also, production of a chemical product may reach at least 1, at least 2, at least 5, at least 10, at least 20, at least 30, at least 40, and at least 50 g/liter titer in various embodiments.
The metrics may be applicable to any of the compositions, e.g., genetically modified microorganisms, methods, e.g., of producing chemical products, and systems, e.g., fermentation systems utilizing the genetically modified microorganisms and/or methods disclosed herein.
It is appreciated that iterative improvements using the strategies and methods provided herein, and based on the discoveries of the interrelationships of the pathways and pathway portions, may lead to even greater chemical product bio-production at the conclusion of a bio-production event.
The novel bioproduction pathways, fermentation processes and genetically modified microorganisms described herein are engineered to produce various chemical products of interest. One chemical product may be a fatty acid of any chain length from 4 to greater than 18 carbons, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 carbon atoms, or more carbon atoms. This group of chemical products includes: butyrate or butyric acid, valerate or valeric acid, caproate or caproic acid, enanthate or enanthic acid, caprylate or caprylic acid, pelargonate or pelargonic acid, caprate or capric acid, undecylate or undecylic acid, laurate or lauric acid, tridecylate or tridecylic acid, myristate or myristic acid, pentadecylate or pentadecylic acid, palmitate or palmitic acid, margarate or margaric acid, stearate or stearic acid, nonadecylate or nonadecylic acid, arachidate or arachidic acid. These fatty acid products may be produced from a fatty acyl-CoA intermediate via the activity of a fatty acyl-CoA thioesterase or wax ester synthase. Alternatively, these fatty acids may be produced from a fatty acyl-CoA intermediate via concerted activities of a fatty acyl-CoA phosphotransferase first producing a fatty acyl-phosphate and then the action of a fatty acid kinase operating to produce a fatty acid from the fatty acyl-phosphate.
Another chemical product may be a fatty aldehyde of any chain length from 4 to greater than 18 carbons, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 carbon atoms, or more carbon atoms. This group of chemical products includes: Butyraldehyde, Valeraldehyde, Caproaldehyde, Enanthaldehyde, Caprylaldehyde, Pelargonaldehyde, Capraldehyde, Undecylaldehyde, Lauraldehyde, Tridecylaldehyde, Myristaldehyde, Pentadecylaldehyde, Palmitaldehyde, Margaraldehyde, Stearaldehyde, Nonadecylaldehyde, and Arachidaldehyde. These aldehyde products may be produced from a fatty acyl-CoA intermediate via the activity of a fatty acyl-CoA reductase or acyl-CoA reductase. Production strains making fatty acids may also be used to produce fatty aldehydes.
Another chemical product may be a fatty alcohol of any chain length from 4 to greater than 18 carbons, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 carbon atoms, or more carbon atoms. This group of chemical products includes: butanol, amyl alcohol, hexanol, heptanol, octanol, nonanol, decanol, hendecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, and eicosanol. These fatty acid products may be produced from a fatty aldehyde via the activity of an aldehyde reductase. Production strains making fatty acids may also be used to produce fatty alcohols by expressing genes encoding enzymes that convert fatty acyl-CoA or free fatty acids to fatty alcohols. Examples of these enzymes include an alcohol-forming acyl-CoA reductase (EC 1.2.1.-), or a long-chain-fatty-acyl-CoA reductase (EC 1.2.1.50) plus an alcohol dehydrogenase (EC 1.1.1.1), or a combination of an aldehyde dehydrogenase (EC 1.2.1.-) and an alcohol dehydrogenase. A polypeptide with fatty acyl-CoA reductase activity is provided by the fabG gene of Acinetobacter SP. ADPL, accession number YP_047869. A polypeptide with fatty-acyl reductase activity is provided by the FAR-N_SDR_e gene of Bombyx mori, accession number BAC79425. A polypeptide with aldehyde dehydrogenase is provided by the ALDH gene of Geobacillus thermodenitrificans NG80-2, accession number YP_001125970. A polypeptide with alcohol dehydrogenase activity is provided by the yqhD gene of E. coli, accession number AP_003562.1. Additional sources of these activities are known to the art and can be combined to generate a production strain that produces fatty alcohols.
Another chemical product may be an alpha olefin of any chain length from 4 to greater than 18 carbons, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 carbon atoms, or more carbon atoms.
Another chemical product may be an alkane of any chain length from 4 to greater than 18 carbons, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 carbon atoms, or more carbon atoms.
Another chemical product may be a diacid of any chain length from 4 to greater than 18 carbons, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 carbon atoms, or more carbon atoms. These fatty acid derived products may be produced from a fatty acid via omega or terminal oxidation by enzymes known in the art.
Any of these may be described herein as a selected chemical product, or a chemical product of interest or as a fatty acid product or as a fatty acid derivative or fatty acid product derivative. Also, any grouping, including any sub-group, of the above listing may be considered what is referred to by “selected chemical product,” “chemical product of interest,” and the like. For any of these chemical products a microorganism may inherently comprise a biosynthesis pathway to such chemical product and/or may require addition of one or more heterologous nucleic acid sequences to provide or complete such a biosynthesis pathway, in order to achieve a desired production of such chemical product.
While various embodiments of the present invention have been shown and described herein, it is emphasized that such embodiments are provided by way of example only. Numerous variations, changes and substitutions may be made without departing from the invention herein in its various embodiments. Specifically, and for whatever reason, for any grouping of compounds, nucleic acid sequences, polypeptides including specific proteins including functional enzymes, metabolic pathway enzymes or intermediates, elements, or other compositions, or concentrations stated or otherwise presented herein in a list, table, or other grouping (such as metabolic pathway enzymes shown in a scheme), unless clearly stated otherwise, it is intended that each such grouping provides the basis for and serves to identify various subset embodiments, the subset embodiments in their broadest scope comprising every subset of such grouping by exclusion of one or more members (or subsets) of the respective stated grouping. Moreover, when any range is described herein, unless clearly stated otherwise, that range includes all values therein and all sub-ranges therein.
Also, and more generally, in accordance with disclosures, discussions, examples and embodiments herein, there may be employed conventional molecular biology, cellular biology, microbiology, and recombinant DNA techniques within the skill of the art. Such techniques are explained fully in the literature. (See, e.g., Sambrook and Russell, “Molecular Cloning: A Laboratory Manual,” Third Edition 2001 (volumes 1-3), Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.; Animal Cell Culture, R. I. Freshney, ed., 1986.) These published resources are incorporated by reference herein for their respective teachings of standard laboratory methods found therein. Such incorporation, at a minimum, is for the specific teaching and/or other purpose that may be noted when citing the reference herein. If a specific teaching and/or other purpose is not so noted, then the published resource is specifically incorporated for the teaching(s) indicated by one or more of the title, abstract, and/or summary of the reference. If no such specifically identified teaching and/or other purpose may be so relevant, then the published resource is incorporated in order to more fully describe the state of the art to which the present invention pertains, and/or to provide such teachings as are generally known to those skilled in the art, as may be applicable. However, it is specifically stated that a citation of a published resource herein shall not be construed as an admission that such is prior art to the present invention. Also, in the event that one or more of the incorporated published resources differs from or contradicts this application, including but not limited to defined terms, term usage, described techniques, or the like, this application controls. Subject matter in the Examples is incorporated into this section to the extent not already present.
The enzyme NphT7 is a 3-keto-acyl-CoA synthase that is active with acetyl-CoA as the primer and malonyl-CoA as the extender donor to generate a 3-keto-C4-CoA product; the native enzyme has no detectable activity on longer chain primers. Residue modifications were made to NphT7 to alter the acyl-CoA binding pocket to accept substrates with chain lengths greater than or equal to 4 carbons. These modifications are single amino acid changes, combinations of single amino acid changes, and targeted structural loop modifications that allow the condensation reaction of acyl-CoAs with chain lengths greater than or equal to 4 carbons, such as C4-CoA and C6-CoA, with malonyl-CoA. The modifications were made based on the following criteria:
(a) Examination of the crystal structure of a related enzyme, the fabH from Mycobacterium tuberculosis (structure 1U6S in the Protein DataBase) identified the residues in Table 16 that contact the acyl chain. The corresponding residues in NphT7 were identified based on homology.
(b) Lid swap mutants. Comparison of the sequence and structural homologies between the mtFabH and NphT7 reveals a predicted L9 loop in NphT7 comprising residues 167-201. The amino acid sequence: GGLTDLIRVPAGGSRQPLDTDGLDAGLQYFAMD, makes up the L9 loops structure corresponding to the acyl-CoA lid. Saturated mutagenesis of the lid (Conversion of each amino acid in the lid to every other amino acid, and combinations of mutations within the lid) may change the lid structure to accept larger acyl-CoA chains.
Mutant nphT7 genes were constructed by oligonucleotide-directed mutagenesis and all mutants were verified to be correct by DNA sequencing. Parent and mutant nphT7 genes were cloned in pET28b vectors in frame with 6 His residues, transformed into E. coli BL21(DE3), and cultures in Terrific Broth containing 35 μg/ml kanamycin were incubated at 37° C. until the OD600 was 0.4. Expression was induced by the addition of 0.1 mM IPTG. Cells were incubated at 18° C. and harvested after 18 hours by centrifugation at 4,000 rpm at 4° C. for 10 minutes. Pellets were stored at −80° C. prior to lysis. Lysates were prepared by resuspending cells in 50 mL Lysis Buffer (25 mM Tris, pH 8.0, 300 mM NaCl, 5 mM β-mercaptoethanol, and benzonase nuclease) and lysing with a Microfluidizer (two passes). Soluble fractions were isolated by centrifugation at 12,000 RPM at 4° C. for 30 minutes. Expression was analyzed by SDS-PAGE (coomassie staining) and anti-His western blotting (4 μg soluble/lane, maintained same volume for soluble/insoluble fraction). NphT7 enzymes were purified by Ni-NTA chromatography. Loop mutants mtloop1 and mtloop2 were additionally purified using DEAE-Sepharose chromatography.
3-ketoacyl-CoA synthase activity was monitored by measuring the release of free CoA-SH using the 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) reagent, malonyl-CoA as the donor substrate, and various primer substrates (acetyl-CoA, C4-CoA, C6-CoA, or C10-CoA). The increase in absorbance at 412 nm at 37° C. (TNB product formation; =14.14 mM−1cm−1 in phosphate buffer at pH 8.0) was used to determine the enzymatic activity. 3-ketoacyl-CoA synthase activity was also monitored by coupling the production of 3-ketoacyl-CoA to the subsequent formation of the 3-hydroxyacyl-CoA product by purified PaFabG and NADPH. Reactions were carried out at room temperature for 30 min, stopped by the addition of acetonitrile to 20% and incubating on ice for 15 minutes, and analyzed by UPLC-MS/MS.
Specific activities of various engineered NphT7 mutants are shown in Table 17. In addition, by measuring the products of the reactions using UPLC-mass spectrometry, it was demonstrated that the variant of NphT7 with the I147T, F217V mutations produces 3-keto-C6-CoA from C4-CoA, 3-keto-C8-CoA from C6-CoA, and 3-keto-C12-CoA from C10-CoA using malonyl-CoA as the extender donor (see
NphT7 is an ideal place to begin forming a strategy for identifying other 3-ketoacyl-CoA synthase candidates because unlike type II FAS 3-ketoacyl-ACP synthases (KAS) that uses malonyl-ACP as an extender, it can perform the targeted reaction using malonyl-CoA and therefore, homologs of NphT7 would likely have maintained specificity for malonyl-CoA. In addition, KAS III from various organisms have been characterized by crystal structures and biochemical assays to define substrate binding sites and substrate specificities. Unlike NphT7, KAS III from various organisms have shown different specificity for longer or branched acyl-CoA. There is similar information available for KAS I and KAS II but unlike KAS III that utilizes acyl-CoA as a substrate for the condensation reaction, they require acyl-ACP as a substrate. Therefore, crystal structures of known KAS III along with biochemical data provide guidance in identifying conserved residues that recognize acyl-CoA and aid in identification of NphT7 homologs that utilize longer chain acyl-CoAs.
E. coli FabH
B. subtilis FabH1
B. subtilis FabH2
S. aureus FabH
S. pneumoniae FabH
M. tuberculosis FabH
aSubstrate specificity determined by enzyme activity
Okamura et al. (PNAS, 2010) defines the biochemical function of NphT7 and compares the amino acid sequence to other NphT7 homologs and E. coli KAS III, FabH (ecFabH). Mainly, the well characterized ecFabH is used to describe the similarities between all NphT7 (NphT7 and 6 NphT7 homologs) and the main differences to KAS III. The information provided by Okaramura et al. with addition of other reports describing other KAS III will be used to define rules for identifying potential 3-ketoacyl-CoA candidates.
The following five strategies for identifying 3-ketoacyl-CoA candidates were used:
Rationale:
Rationale:
Rationale:
Rationale:
Rationale:
The following summarizes the results from the five strategies for identifying 3-ketoacyl-CoA candidates outlined above:
1. Homology Search of NphT7
2. Select for NphT7 Homologs with (A/G)GGSR Motif
3. Elimination of Homologs with STPDXPQ Sequence Motif
4. Selection Based on Conservation of Hydrophobic Residues in the Substrate Binding Pocket
5. Selection Based on Evolutionary Distance from NphT7 and Known KAS III
lists the 3-ketoacyl-CoA synthase chosen based on the criteria described above. In addition, each synthase was aligned to NphT7, ecFabH, mtFabH, and saFabH to determine percent sequence identity, similarity and gap. Synthases 1-10 are chosen based on having all criteria met. Synthases 11-21 are chosen based on having all criteria met except for conserved hydrophobic residues. Synthase 22 is chosen based on having (A/G)GGSR sequence motif
Rhodothermus
marinus
Streptomyces
davawensis ICM
Chlamydophila
pecorum E58
Clostridium
ultense Esp
Corallococcus
coralloides DSM
Desmospora sp.
Paenibacillus
peoriae KCTC
Pelosinus
fermentans DSM
Candidatus
Solibacter usitatus
Desulfotomaculum
nigrificans
Saccharomonospora
glauca K62
Corallococcus
coralloides
Legionella
pneumophila str.
Streptomyces
avermitilis
Verrucosispora
maris AB-18-032
Rhodopirellula
baltica SH 1
Candidatus
Methylomirabilis
oxyfera
Thermaerobacter
marianensis DSM
Caldisericum
exile AZM16c01
Indibacter
alkaliphilus LW1
Candidatus
Amoebophilus
asiaticus 5a2
Flavobacterium
While mutants of NphT7 were engineered that are capable of extending acyl-CoAs of chain length C4, C6, and C10, the specific activities of these enzymes are relatively low for the higher chain lengths. The extension by 2 carbon lengths of acyl-CoAs to form 3-keto-acyl-CoAs is a reaction also carried out by keto-acyl-CoA synthases known as KASIII enzymes, encoded by fabH gene homologs. A number of such gene homologs were synthesized using codons for optimal expression in E. coli by a commercial DNA synthesis provider (DNA2.0) and fused with 6 His residues at the N-terminus for purification of the proteins by affinity chromatography. The genes were expressed in E. coli and KAS activity was assayed using the DTNB assay for CoA-SH release from the condensation of malonyl-CoA with acyl-CoAs of varying chain lengths. Table 20 lists the enzyme homologs with sufficiently high level KAS activity to enable such enzymes to extend the acyl-CoAs of the various chain lengths noted in the table. As may be seen from the results in Table 20, FabH enzymes from different sources have different substrate chain-length preferences.
Streptomyces sp. (strain CL190)
Pelosinus fermentans DSM 17108
Saccharomonospora glauca K62
Verrucosispora maris AB-18-032
Clostridiales bacterium 1_7_47_FAA
Streptomyces sp. (strain CL190)
Saccharomonospora glauca K62
Saccharomonospora azurea NA-128
Mesorhizobium sp. STM 4661
Clostridiales bacterium 1_7_47_FAA
Gordonia aichiensis NBRC 108223
Arcobacter butzleri ED-1
Clostridiales bacterium 1_7_47_FAA
Saccharomonospora glauca K62
Ralstonia solanacearum Po82
Gordonia aichiensis NBRC 108223
Gluconacetobacter oboediens 174Bp2
Arcobacter butzleri ED-1
Ralstonia solanacearum Po82
Phaeobacter gallaeciensis 2.10
Alishewanella aestuarii B11
Streptomyces sp. (strain CL190)
A further approach to chain length specificity can be achieved by targeting the release of fatty acids from the acyl-CoA precursor. The genes encoding a variety of thioesterases were synthesized using codons optimized for expression in E. coli by a commercial DNA synthesis provider (DNA2.0) and the genes expressed. Purification of the enzymes was enabled by affinity chromatography based on the N-terminal 6His affinity tag. The activity of this variety of thioesterases on acyl-CoAs of different chain lengths was assessed (
Thus the incorporation of an NphT7 variant, a FabH with the desired specificity as shown in Table 20, and the appropriate thioesterase as shown in
A number of genetically modified E. coli strains were evaluated for production of free fatty acids. These strains comprise an engineered host based on strain BW25113 and with the additional genetic modifications: ΔldhA::frt, ΔpflB::frt, ΔmgsA::frt, ΔpoxB::frt, Δpta-ack::frt; a temperature-sensitive allele of fabI (fabIts S241F); and the additional modifications: Δtig::frt, ΔatoDAEB::frt, ΔfadD::frt that minimize diversion of acyl-CoA substrates or fatty acid products. Genes encoding NphT7, one or more thioesterases, a keto-CoA reductase (KCR), a 3-hydroxy-acyl-CoA dehydratase (3HDh), and an enoyl-CoA reductase (EnCr) are also provided on plasmids. The genes present in samples 1-5 are depicted in Table 21.
The rate of producing C8-C18 FFA by these samples is shown in
Alternative KCRs, 3HDh, and EnCr enzymes may be used to provide the requisite activities to convert the keto-acyl-CoA product of NphT7, NphT7 mutants, or fabH homologs to the fully saturated product elongated by 2 carbons, viz. the reduction of the keto-acyl-CoA to 3-hydroxyacyl-CoA by KCR, the dehydration of the 3-hydroxyacyl-CoA to the enoyl-CoA by 3HDh, and the reduction of the enoyl-CoA to acyl-CoA by EnCr. For example, alternative KCRs including FadIJ, Hbd, and FadB. FadB has sufficient activity as a KCR up to C16 (See the Table 22 below).
Alternative 3HDhs including the bifunctional FadB, FabG, FadJ, and Hbd were tested for activity and product specificity. The results are shown in
To prevent consumption of the fatty acid product and to maintain chain length specificity, additional host genetic modifications to eliminate thioesterases may be required. These modifications include deletion or modulation of tesB, yciA, fadM, ybgC, and ybfF.
It was demonstrated that odd chain length fatty acids can be produced using the genetically modified enzymes and methods of the present invention. In particular, it was demonstrated that the enzymes NphT7 and NphT7 mutants are active with propionyl-CoA as the primer and malonyl-CoA as the extender donor to generate C5 keto-acyl-CoA. The NphT7 variants and fabHs described herein would further extend the C5 keto-acyl-CoA to make longer chain odd-numbered fatty acid products.
Freshly purified His6-NphT7, His6-NphT7(I147T, F217V), His6-NphT7(I147S, F217V), and His6-Hbd were used in all the experiments in this example. NphT7 reactions (200 μL) contained 100 mM Tris-HCl (pH 8), 5 mM MgCl2, 1 mM malonyl-CoA, 1 mM primer CoA (C2-, or C3-COA), and various concentrations of wild-type NphT7 or mutant enzymes. Reactions without any primer CoA but with malonyl-CoA were also run. Formation of Mg2+-3-keto-acyl-CoA adduct was monitored at 303 nm, at 37° C. for 15 min. NphT7-Hbd coupled reactions (200 μL) contained 100 mM Tris-HCl (pH 8), 0.75 mM NADH, 1 mM malonyl-CoA, 1 mM primer CoA (C2 or C3-COA), 10 μg of partially purified Hbd, and various concentrations of wild-type NphT7 or mutant enzymes. Reactions without any primer CoA but with malonyl-CoA were also run. Oxidation of NADH was followed at 340 nm, at 37° C. for 15 min. At the end of the 15-minute enzyme reactions, 100 μL of samples were removed from each reaction and immediately mixed with 25 μL acetonitrile to terminate enzyme reactions. The mixtures were incubated on ice for at least 15 min, followed by centrifugation at 3,220×g at 4° C. for 15 min. Supernatants were saved for UPLC-MS/MS analyses for the detection of 3-keto- and 3-OH—C4 and C5-COA. In certain runs, the Hbd enzyme was also used to determine if keto-CoA produced could be reduced to hydroxyacyl-CoA. The experimental results are shown in Table 23.
3-keto-05-CoA was produced by NphT7 only when C3- and malonyl-CoA were present simultaneously (Table 23—Run 2). When NphT7 was coupled to Hbd, the majority of the 3-keto-05-CoA was reduced to 3-OH-05-CoA. These results indicated that wild-type NphT7 is capable of utilizing a C3-CoA as primer in synthesizing 3-keto-05-CoA, and Hbd from Clostridium acetobutylicum is capable of reducing 3-keto-05-CoA.
Reactions using either NphT7 (I147T, F217V) or NphT7 (I147S, F217V) mutants were similar to those obtained in wild-type NphT7 reactions. Both mutants could use C3-CoA as primer to produce 3-keto-05-CoA, which was further reduced to 3-OH-05-CoA in the presence of Hbd plus NADH (Table 23—Runs 7-18). With acetyl-CoA plus malonyl-CoA or malonyl-CoA alone, only 3-keto-C4-CoA was produced by these enzymes. Higher concentrations of products were detected in either NphT7 (I147T, F217V) or NphT7 (I147S, F217V) because more enzymes were used in these 2 reactions than the reactions with wild-type NphT7.
When 3-keto-05-CoA concentrations were plotted against the amount of enzymes in each reaction, specific activities (average over 15 min) of NphT7, NphT7 (I147T, F217V), and NphT7 (I147S, F217V) were 0.3, 0.2, and 0.27 U/mg, respectively.
Production of odd chain fatty acids, such as fatty acids of C5, C7, C9, C11, C13, C15, and C17 in length, is made possible by the construction of recombinant strains carrying genes expressing NphT7 and/or an NphT7 mutant, a fabH with the desired chain length specificity, a KCR, a 3HDh, and an EnCr, and a terminating enzyme such as a thioesterase or an ester synthase with the desired chain length specificity, and providing a source of propionyl-CoA as the primer and malonyl-CoA as the extender.
It was demonstrated that C4 and C6 fatty acids can be produced using the genetically modified enzymes and methods of the present invention. In particular, it was demonstrated that C4 and C6 fatty acids can be produced by microorganisms genetically modified to encode certain NphT7 mutant enzymes in combination with PA2801TE thioesterase. These amino acid modifications enable the condensation reaction of acyl-CoA (C4-CoA and C6-CoA) with malonyl-CoA. In particular, the genetically modified microorganism comprises one or more heterologous 3-ketoacyl-CoA synthases selected from the group comprising wild-type NphT7, a variant of NphT7 with the I147T and F217V mutations, or a variant of NphT7 with I147S and F217V mutations, and any combination thereof, and at least one of: a) a heterologous KCR, such as fadB; b) a heterologous 3HDh, such as a fadB, c) a heterologous EnCr, such as ter; and d) a thioesterase PA2801TE.
The following genetically modified E. coli strains were evaluated for production of free fatty acids:
A single colony was incubated at 30° C. for 20 hours in 150 ml SM11 with 35 μg/ml Kanamycin and 20 μg/ml Chloramphenicol. The cultures were transferred to 50 mL conical tubes and centrifuged at 4,000 RPM for 15 minutes. The pellets were resuspended in fresh SM11 (with phosphate) media to an optical density of 20. The resuspensions of each strain were combined, and 2.5 ml (5%) of the combined resuspensions was used to inoculate 50 ml of SM11 without phosphate media. The culture was incubated for 4 hours at 30° C., and thereafter the temperature was shifted to 37° C. After an additional 20 hours, samples were taken and analyzed for the amount of free fatty acid present. The amounts of C4, C6, and total free fatty acid measured as C4-C18 produced are shown in
C4, C6 and C8 fatty acids were produced using the genetically modified enzymes and methods of the present invention. In particular, C4, C6 and C8 fatty acids were produced by microorganisms genetically modified to encode certain NphT7 mutant enzymes in combination with thioesterases. These amino acid modifications enable the condensation reaction of acyl-CoA (C2-CoA, C4-CoA, and C6-CoA) with malonyl-CoA. The genetically modified microorganism comprises one or more heterologous 3-ketoacyl-CoA synthases selected from the group comprising wild-type NphT7, or a variant of NphT7 with I147S and F217V mutations, and any combination thereof, and at least one of: a) a heterologous KCR, such as fadB; b) a heterologous 3HDh, such as a fadB, c) a heterologous EnCr, such as ter; and d) a thioesterase ‘tesA.
The following genetically modified E. coli strains were evaluated for production of free fatty acids:
Production of fatty acids of chain length >C8, such as C10, C12, C14, C16, and C18 fatty acids in length with high specificity, is made possible by the construction of recombinant strains carrying genes expressing NphT7 and/or an NphT7 mutant, a fabH with the desired chain length specificity, a KCR, a 3HDh, and an EnCr, and a terminating enzyme such as a thioesterase or an ester synthase with the desired specificity, and providing a source of acetyl-CoA as the primer and malonyl-CoA as the extender.
While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention.
The present application claims the benefit of U.S. Provisional Patent Application No. 61/856,652 (Attorney Docket No. 34246-780.101) filed on Jul. 19, 2013, the entire contents of which are incorporated herein by reference.
This invention was made with Government support under DE-AR0000088 awarded by the United States Department of Energy. The Government has certain rights in this invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2014/047320 | 7/18/2014 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61856652 | Jul 2013 | US |
