Patent Application
20090221033
The present invention relates to lipase variants with an improved wash effect to odor generation and to a method of preparing them. It particularly relates to variants of the Thermomyces lanuginosus lipase.
The present application contains a computer-readable form of a sequence listing, which is fully incorporated herein by reference.
Lipases are useful, e.g., as detergent enzymes to remove lipid or fatty stains from clothes and other textiles, and as additives to dough for bread and other baked products. Thus, a lipase derived from Thermomyces lanuginosus (synonym Humicola lanuginosa, EP 258068 and EP 305216) is sold for detergent use under the trade name Lipolase® (product of Novozymes A/S). WO 0060063 describes variants of the T. lanuginosus lipase with a particularly good first-wash performance in a detergent solution. WO 9704079, WO 9707202 and WO 0032758 also disclose variants of the T. lanuginosus lipase.
In some applications, it is of interest to minimize the formation of odor-generating short-chain fatty acids. Thus, it is known that laundry detergents with lipases may sometimes leave residual odors attached to cloth soiled with milk (EP 430315). WO 02062973 discloses lipase variants where the odor generation has been reduced by attaching a C-terminal extension. The recently published WO 07087508 discloses lipase variants where the odor generation has been reduced by introducing mutations in one or more regions identified in a parent lipase. WO 07087503 describes polypeptides having lipase activity and which further has a RP of at least 0.8 and a BR of at least 1.1 at the test conditions given in the specification.
In a first aspect, the invention relates to a first polypeptide having lipase activity wherein said polypeptide is a polypeptide having at least one of: (a) a lipase activity (LU) relative to the absorbance at 280 nm (A280) of less than 500 LU/A280, in which one unit of LU (1 LU) is defined as the amount of enzyme capable of releasing 1 micro mol of butyric acid per minute at 30° C. at pH 7, and the absorbance of the polypeptide is measured at 280 nm; (b) a Risk performance odor (R) below 0.5, in which R is calculated as the ratio between the amount butyric acid released from a polypeptide washed swatch and the amount butyric acid released from a reference polypeptide washed swatch, after both values have been corrected for the amount of butyric acid released from a non-polypeptide washed swatch; or (c) a Benefit Risk factor (BR) of at least 1.8, in which BR is defined as the average wash performance (RPavg) divided with the risk performance odor (R).
In a second aspect, the invention relates to a second polypeptide having lipase activity comprising alterations of the amino acids at the positions T231R+N233R+I255A+P256K and at least one of (a) S58A+V60S+A150G+L227G; or (b) E210V/G; which positions are corresponding to SEQ ID NO: 2.
In further aspects, the invention relates to an isolated polynucleotide encoding the polypeptide having lipase activity, a nucleic acid construct comprising the polynucleotide, a recombinant expression vector comprising the nucleic acid construct, and a transformed host cell comprising the nucleic acid construct or the recombinant expression vector.
In a further aspect, the invention relates to a method of preparing the polypeptide comprising the steps: (a) cultivating the transformed host cell comprising the nucleic acid construct or the recombinant expression vector comprising the polypeptide under conditions conductive for the production of the polypeptide; and (b) recovering the polypeptide.
In a further aspect, the invention relates to a formulation comprising the polypeptide.
In a further aspect, the invention relates to a method of reducing the formation of odor generating short chain fatty acids during lipid hydrolysis by employing the polypeptide.
SEQ ID NO: 1 shows the DNA sequence encoding lipase from Thermomyces lanoginosus.
SEQ ID NO: 2 shows the amino acid sequence of a lipase from Thermomyces lanoginosus.
SEQ ID NO: 3 shows the amino acid sequence of a lipase from Absidia reflexa.
SEQ ID NO: 4 shows the amino acid sequence of a lipase from Absidia corymbifera.
SEQ ID NO: 5 shows the amino acid sequence of a lipase from Rhizomucor miehei.
SEQ ID NO: 6 shows the amino acid sequence of a lipase from Rhizopus oryzae.
SEQ ID NO: 7 shows the amino acid sequence of a lipase from Aspergillus niger.
SEQ ID NO: 8 shows the amino acid sequence of a lipase from Aspergillus tubingensis.
SEQ ID NO: 9 shows the amino acid sequence of a lipase from Fusarium oxysporrum.
SEQ ID NO: 10 shows the amino acid sequence of a lipase from Fusarium heterosporum.
SEQ ID NO: 11 shows the amino acid sequence of a lipase from Aspergillus oryzae.
SEQ ID NO: 12 shows the amino acid sequence of a lipase from Penicillium camemberti.
SEQ ID NO: 13 shows the amino acid sequence of a lipase from Aspergillus foetidus.
SEQ ID NO: 14 shows the amino acid sequence of a lipase from Aspergillus niger.
SEQ ID NO: 15 shows the amino acid sequence of a lipase from Aspergillus oryzae.
SEQ ID NO: 16 shows the amino acid sequence of a lipase from Landerina penisapora.
Use of lipases to remove lipid and fatty stains is known in the art where the activities of lipases that result in release of free short chain lipids, such as e.g. butyric acid are associated with an undesirable odor. Hydrolysis of the substrate tributyrin results in the release of butyric acid. The polypeptides of the present invention have surprisingly been found to have a low specific activity, measured as LU/A280; towards tributyrin at neutral pH cf. example 2 and table 3.
The Benefit Risk factor (BR) is calculated by dividing the relative (wash) performance (benefit, RP) with the risk performance odor (risk, R). The wash performance may be measured by an automated mechanical stress assay (AMSA) cf. example 3, and the odor generation may be measured directly by gas chromatography, cf. example 4 and table 3. A reduced odor affects the BR and may lead to an increase in BR. The polypeptides of the present invention have furthermore been found to have a reduced odor generation and an increased BR over the lipases known in the art cf. example 5 and table 3.
Lipase activity (LU): The term “lipase activity” as used herein means a carboxylic ester hydrolase activity which catalyses the hydrolysis of triacylglycerol under the formation of diacylglycerol and a carboxylate. For the purpose of the present invention, lipase activity is determined according to the following procedure: A substrate for lipase is prepared by emulsifying tributyrin (glycerin tributyrate) using gum Arabic as emulsifier. The hydrolysis of tributyrin at 30° C. at pH 7 or 9 is followed in a pH-stat titration experiment. One unit of lipase activity (1 LU) is defined as the amount of enzyme capable of releasing 1 micro mol of butyric acid per minute at 30° C., pH 7.
Risk performance odor (R): The term “risk performance odor” as used herein means the ratio between the amount butyric acid released from a polypeptide washed swatch and the amount butyric acid released from a reference polypeptide washed swatch, after both values have been corrected for the amount of butyric acid released from a non-polypeptide washed swatch.
Relative performance (RP): The term “relative performance” as used herein means the wash performance of the polypeptide compared to the wash performance of a reference polypeptide. For the purpose of the present invention, relative performance is determined according to the procedure described in example 3.
Reference polypeptide: The term “reference polypeptide”, “reference enzyme” or “reference lipase” as used herein means the mature part of SEQ ID NO: 2 with the substitutions T231R+N233R.
Benefit Risk factor (BR): The term “Benefit Risk factor” as used herein means the average relative performance (RPavg) compared to the risk for odor generation (R) and has the following formula: BR=RPavg/R.
In describing lipase variants according to the invention, the following nomenclature is used for ease of reference:
According to this nomenclature, for instance the substitution of glutamic acid for glycine in position 195 is shown as G195E. A deletion of glycine in the same position is shown as G195*, and insertion of an additional amino acid residue such as lysine is shown as G195GK. Where a specific lipase contains a “deletion” in comparison with other lipases and an insertion is made in such a position this is indicated as *36D for insertion of an aspartic acid in position 36.
Multiple mutations are separated by pluses, i.e.: R170Y+G195E, representing mutations in positions 170 and 195 substituting tyrosine and glutamic acid for arginine and glycine, respectively.
X231 indicates the amino acid in a parent polypeptide corresponding to position 231, when applying the described alignment procedure. X231R indicates that the amino acid is replaced with R. For SEQ ID NO: 2 X is T, and X231R thus indicates a substitution of T in position 231 with R. Where the amino acid in a position (e.g. 231) may be substituted by another amino acid selected from a group of amino acids, e.g. the group consisting of R and P and Y, this will be indicated by X231R/P/Y.
In all cases, the accepted IUPAC single letter or triple letter amino acid abbreviation is employed.
Identity: The term “identity” as used herein means the relatedness between two amino acid sequences or between two nucleotide sequences is described by the parameter “identity”.
For purposes of the present invention, the alignment of two amino acid sequences is determined by using the Needle program from the EMBOSS package (http://emboss.org) version 2.8.0. The Needle program implements the global alignment algorithm described in Needleman, S. B. and Wunsch, C. D. (1970) J. Mol. Biol. 48, 443-453. The substitution matrix used is BLOSUM62, gap opening penalty is 10, and gap extension penalty is 0.5.
The degree of identity between an amino acid sequence of the present invention (“invention sequence”; e.g. amino acids 1 to 269 of SEQ ID NO: 2) and a different amino acid sequence (“foreign sequence”) is calculated as the number of exact matches in an alignment of the two sequences, divided by the length of the “invention sequence” or the length of the “foreign sequence”, whichever is the shortest. The result is expressed in percent identity.
An exact match occurs when the “invention sequence” and the “foreign sequence” have identical amino acid residues in the same positions of the overlap. The length of a sequence is the number of amino acid residues in the sequence (e.g. the length of SEQ ID NO: 2 are 269).
The above procedure may be used for calculation of identity as well as homology and for alignment. In the context of the present invention homology and alignment has been calculated as described below.
For purposes of the present invention, the degree of homology may be suitably determined by means of computer programs known in the art, such as GAP provided in the GCG program package (Program Manual for the Wisconsin Package, Version 8, August 1994, Genetics Computer Group, 575 Science Drive, Madison, Wis., USA 53711) (Needleman, S. B. and Wunsch, C. D., (1970), Journal of Molecular Biology, 48, 443-45), using GAP with the following settings for polypeptide sequence comparison: GAP creation penalty of 3.0 and GAP extension penalty of 0.1.
In the present invention, corresponding (or homologous) positions in the lipase sequences of Absidia reflexa, Absidia corymbefera, Rhizmucor miehei, Rhizopus delemar, Aspergillus niger, Aspergillus tubigensis, Fusarium oxysporum, Fusarium heterosporum, Aspergillus oryzea, Penicilium camembertii, Aspergillus foetidus, Aspergillus niger, Thermomyces lanoginosus (synonym: Humicola lanuginose) and Landerina penisapora are defined by the alignment shown in
To find the homologous positions in lipase sequences not shown in the alignment, the sequence of interest is aligned to the sequences shown in
Any suitable polypeptide may be used. In some embodiments the polypeptide may be a fungal polypeptide.
The polypeptide may be a yeast polypeptide originating from genera such as a Candida, Kluyveromyces, Pichia, Saccharomyces, Schizosaccharomyces, or Yarrowia; or more preferably a filamentous fungal polypeptide originating from genera such as a Acremonium, Aspergillus, Aureobasidium, Cryptococcus, Filobasidium, Fusarium, Humicola, Magnaporthe, Mucor, Myceliophthora, Neocallimastix, Neurospora, Paecilomyces, Penicllium, Piromyces, Schizophyllum, Talaromyces, Thermoascus, Thielavia, Tolypocladium, Thermomyces or Trichoderma.
The polypeptide may furthermore be a Saccharomyces carlsbergensis, Saccharomyces cerevisiae, Saccharomyces diastaticus, Saccharomyces douglasii, Saccharomyces kluyveri, Saccharomyces norbensis, or Saccharomyces oviformis polypeptide having lipase activity.
Alternatively, the polypeptide is an Aspergillus aculeatus, Aspergillus awamori, Aspergillus fumigatus, Aspergillus foetidus, Aspergillus japonicus, Aspergillus nidulans, Aspergillus niger, Aspergillus oryzae, Aspergillus turbigensis, Fusarium bactridioides, Fusarium cerealis, Fusarium crookwellense, Fusarium culmorum, Fusarium graminearum, Fusarium graminum, Fusarium heterosporum, Fusarium negundi, Fusarium oxysporum, Fusarium reticulatum, Fusarium roseum, Fusarium sambucinum, Fusarium sarcochroum, Fusarium sporotrichioides, Fusarium sulphureum, Fusarium torulosum, Fusarium trichothecioides, Fusarium venenatum, Humicola insolens, Thermomyces lanoginosus (synonym: Humicola lanuginose), Mucor miehei, Myceliophthora thermophila, Neurospora crassa, Penicillium purpurogenum, Trichoderma harzianum, Trichoderma koningii, Trichoderma longibrachiatum, Trichoderma reesei, or Trichoderma viride polypeptide.
In some embodiments the invention relates to a polypeptide which is a Thermomyces lipase.
In some embodiments the invention relates to a polypeptide which is a Thermomyces lanuginosus lipase.
In some embodiments the invention relates to a polypeptide, wherein the polypeptide is at least 50%, at least 60%, at least 70%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% identical to SEQ ID NO: 2.
The positions referred to below are the positions of the amino acid residues in SEQ ID NO: 2. The procedure described in the paragraph “Homology and alignment” is used to find the corresponding or homologous position of the amino acid residue in a different lipase.
In some embodiments the invention relates to a first polypeptide having lipase activity wherein said polypeptide is a polypeptide having at least one of: (a) a lipase activity (LU) relative to the absorbance at 280 nm (A280) of less than 500, less than 450, less than 400, less than 350, less than 300, less than 250, less than 200, less than 150, less than 100 or less than 50 LU/A280, in which one unit of LU (1 LU) is defined as the amount of enzyme capable of releasing 1 micro mol of butyric acid per minute at 30° C. at pH 7, and the absorbance of the polypeptide is measured at 280 nm; (b) a Risk performance odor (R) below 0.5, below 0.4, below 0.3, below 0.2, below 0.1, or below 0.05, in which R is calculated as the ratio between the amount butyric acid released from a polypeptide washed swatch and the amount butyric acid released from a reference polypeptide washed swatch, after both values have been corrected for the amount of butyric acid released from a non-polypeptide washed swatch; or (c) a Benefit Risk factor (BR) of at least 1.8, at least 1.9, at least 2.0, at least 2.5, at least 3.0, at least 4.0, at least 5.0, or at least 6.0 in which BR is defined as the average wash performance (RPavg) divided with the risk performance odor (R).
In some embodiments the invention relates to the first polypeptide wherein said polypeptide comprises alterations of the amino acids at the positions T231R+N233R+1255A+P256K and at least one of (a) S58A+V60S+A150G+L227G; or (b) E210V/G; which positions are corresponding to SEQ ID NO: 2.
In some embodiments the invention relates to the first polypeptide further comprising at least one of the alteration of the amino acid at the positions 186V or T143S.
In some embodiments the invention relates to the first polypeptide, wherein the polypeptide comprises at least one further alteration selected from a substitution, a deletion or an addition of at least one amino acid at a position corresponding to position E1, D27, N33, S83, G91, N94, K98, E99, D102, D111N, G163K, I202L, E210, S216, L259 or L269 of SEQ ID NO: 2.
In some embodiments the invention relates to the first polypeptide, wherein the at least one alteration is selected from the group consisting of: E1N/*, D27N, N33Q, S83T, G91N, N94R, K98I, E99K, D102A, D111N, G163K, 1202L, E210A, S216P, L259F, or L269APIA of SEQ ID NO: 2.
In some embodiments the invention relates to a second polypeptide comprising alterations of the amino acids at the positions T231R+N233R+1255A+P256K and at least one of: (a) S58A+V60S+A150G+L227G; or (b) E210V/G; which positions are corresponding to SEQ ID NO: 2.
In some embodiments the invention relates to the second polypeptide further comprising at least one of the alterations of the amino acid at the positions 186V or T143S.
In some embodiments the invention relates to the second polypeptide, wherein the polypeptide comprises at least one further alteration selected from a substitution, a deletion or an addition of at least one amino acid at a position corresponding to position E1, D27, N33, S83, G91, N94, K98I, E99, D102, D111, G163, I202, E210, S216, L259 or L269 of SEQ ID NO: 2.
In some embodiments the invention relates to the second polypeptide, wherein the at least one alteration is selected from the group consisting of: E1N/*, D27N, N33Q, S83T, G91N, N94R, K98I, E99K, D102A, D111N, G163K, 1202L, E210A, S216P, L259F, or L269APIA of SEQ ID NO: 2.
In some embodiments the invention relates to the first polypeptide, wherein said polypeptide comprises alterations selected from the group consisting of: (a) T231R+N233R+L269APIA; (b) S58T+V60K+A150G+T231R+N233I+D234G; (c) S58T+V60K+186V+D102A+A150G+L227G+T231R+N233R+P256K; (d) S58N+V60S+186P+T231R+N233R+P256S; (e) S58N+V60S+I86S+L227G+T231R+N233R+P256S; and (f) S58N+V60S+186T+L227G+T231R+N233R+P256L.
In some embodiments the invention relates to the first or the second polypeptide, wherein said polypeptide comprises alterations selected from the group consisting of: (a) S58A+V60S+S83T+A150G+L227G+T231R+N233R+1255A+P256K; (b) S58A+V60S+186V+A150G+L227G+T231R+N233R+1255A+P256K; (c) S58A+V60S+186V+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (d) S58A+V60S+186V+T143S+A150G+G163K+S216P+L227G+T231R+N233R+1255A+P256K; (e) E1*+S58A+V60S+186V+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (f) S58A+V60S+186V+K98I+E99K+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (g) E1N+S58A+V60S+186V+K98I+E99K+T143S+A150G+L227G+T231R+N233R+1255A+P256K+L259F; (h) S58A+V60S+I86V+K98I+E99K+D102A+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (i) N33Q+S58A+V60S+186V+T143S+A150G+L227G+T231R+N233R+I255A+P256K; (j) E1*+S58A+V60S+186V+K98I+E99K+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (k) E1N+S58A+V60S+186V+K98I+E99K+T143S+A150G+S216P+L227G+T231R+N233R+1255A+P256K; (l) D27N+S58A+V60S+186V+G91N+N94R+D111N+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (m) E1N+S58A+V60S+186V+K98I+E99K+T143S+A150G+E210A+S216P+L227G+T231R+N233R+1255A+P256K; (n) A150G+E210V+T231R+N233R+1255A+P256K; (o) 1202L+E210G+T231R+N233R+1255A+P256K; (p) E1N+A18K+V60K+186V+A150G+E210A+L227G+T231R+N233R+P256K; (q) E1L+D27K+V60K+186V+A150G+S219P+L227G+T231R+N233R+P256K; (r) E1N+S58A+V60S+S83T+A150G+L227G+T231R+N233R+1255A+P256K; (s) E1N+S58T+V60K+I86V+D102A+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (t) E1N+S58A+V60S+186V+K98I+E99K+D102A+T143S+A150G+S216P+L227G+T231R+N233R+I255A+P256K; and (u) S58A+V60S+S83T+A150A+L227G+T231R+N233R+1255A+P256K.
In some embodiments the invention relates to a first polypeptide, wherein said polypeptide comprises alterations selected from the group consisting of: (a) T231R+N233R+L269APIA; (b) S58T+V60K+A150G+T231R+N2331+D234G; (c) S58T+V60K+186V+D102A+A150G+L227G+T231R+N233R+P256K; (d) S58N+V60S+186P+T231R+N233R+P256S; (e) S58N+V60S+186S+L227G+T231R+N233R+P256S; and (f) S58N+V60S+186T+L227G+T231R+N233R+P256L.
In some embodiments the invention relates to a first or a second polypeptide, wherein said polypeptide comprises alterations selected from the group consisting of: (a) S58A+V60S+S83T+A150G+L227G+T231R+N233R+1255A+P256K; (b) S58A+V60S+186V+A150G+L227G+T231R+N233R+1255A+P256K; (c) S58A+V60S+186V+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (d) S58A+V60S+186V+T143S+A150G+G163K+S216P+L227G+T231R+N233R+1255A+P256K; (e) E1*+S58A+V60S+186V+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (f) S58A+V60S+186V+K981+E99K+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (g) E1N+S58A+V60S+186V+K98I+E99K+T143S+A150G+L227G+T231R+N233R+1255A+P256K+L259F; (h) S58A+V60S+I86V+K98I+E99K+D102A+T143S+A150G+L227G+T231R+N233R+I255A+P256K; (i) N33Q+S58A+V60S+186V+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (j) E1*+S58A+V60S+186V+K98I+E99K+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (k) E1N+S58A+V60S+186V+K98I+E99K+T143S+A150G+S216P+L227G+T231R+N233R+1255A+P256K; (l) D27N+S58A+V60S+186V+G91N+N94R+D111N+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (m) E1N+S58A+V60S+186V+K98I+E99K+T143S+A150G+E210A+S216P+L227G+T231R+N233R+I255A+P256K; (n) A150G+E210V+T231R+N233R+1255A+P256K; (o) I202L+E210G+T231R+N233R+1255A+P256K; (p) E1N+A18K+V60K+186V+A150G+E210A+L227G+T231R+N233R+P256K; (q) E1L+D27K+V60K+186V+A150G+S219P+L227G+T231R+N233R+P256K; (r) E1N+S58A+V60S+S83T+A150G+L227G+T231R+N233R+1255A+P256K; (s) E1N+S58T+V60K+186V+D102A+T143S+A150G+L227G+T231R+N233R+1255A+P256K; (t) E1N+S58A+V60S+186V+K98I+E99K+D102A+T143S+A150G+S216P+L227G+T231R+N233R+I255A+P256K; and (u) S58A+V60S+S83T+A150A+L227G+T231R+N233R+1255A+P256K.
In some embodiments the invention relates to an isolated polynucleotide encoding the polypeptide. Such polynucleotides may hybridize under very low stringency conditions, preferably low stringency conditions, more preferably medium stringency conditions, more preferably medium-high stringency conditions, even more preferably high stringency conditions, and most preferably very high stringency conditions with (i) nucleotides 178 to 660 of SEQ ID NO: 1, (ii) the cDNA sequence contained in nucleotides 178 to 660 of SEQ ID NO: 1, (iii) a subsequence of (i) or (ii), or (iv) a complementary strand of (i), (ii), or (iii) (J. Sambrook, E. F. Fritsch, and T. Maniatus, 1989, Molecular Cloning, A Laboratory Manual, 2d edition, Cold Spring Harbor, N.Y.). A subsequence of SEQ ID NO: 1 contains at least 100 contiguous nucleotides or preferably at least 200 contiguous nucleotides. Moreover, the subsequence may encode a polypeptide fragment which has lipase activity.
For long probes of at least 100 nucleotides in length, very low to very high stringency conditions are defined as prehybridization and hybridization at 42° C. in 5×SSPE, 0.3% SDS, 200 ug/ml sheared and denatured salmon sperm DNA, and either 25% formamide for very low and low stringencies, 35% formamide for medium and medium-high stringencies, or 50% formamide for high and very high stringencies, following standard Southern blotting procedures for 12 to 24 hours optimally.
For long probes of at least 100 nucleotides in length, the carrier material is finally washed three times each for 15 minutes using 2×SSC, 0.2% SDS preferably at least at 45° C. (very low stringency), more preferably at least at 50° C. (low stringency), more preferably at least at 55° C. (medium stringency), more preferably at least at 60° C. (medium-high stringency), even more preferably at least at 65° C. (high stringency), and most preferably at least at 70° C. (very high stringency).
In some embodiments the invention relates to a nucleic acid construct comprising the polynucleotide operationally linked to at least one control sequence that directs the production of the polypeptide in an expression host.
In some embodiments the invention relates to a recombinant expression vector comprising the nucleic acid construct.
In some embodiments the invention relates to a transformed host cell comprising the nucleic acid construct or the recombinant expression vector.
The isolated polynucleotide encoding the polynucleotide, the nucleic acid construct comprising the polynucleotide, the recombinant expression vector comprising the nucleic acid construct, and the transformed host cell comprising the nucleic acid construct or the recombinant expression vector may all be obtained by methods known in the art.
In some embodiments the invention relates to a method of preparing the polypeptide comprising the steps: (a) cultivating the transformed host cell comprising the nucleic acid construct or the recombinant expression vector comprising the nucleotide acid construct under conditions conductive for the production of the polypeptide; and (b) recovering the polypeptide. The method may be practiced according to principles known in the art.
Enzymes of the present invention may be used, incl. industrial use for removing of fatty matter.
In some embodiments the invention relates to a formulation comprising the polypeptide. In further embodiments the invention relates to a formulation, wherein said formulation may be a solid or a liquid formulation. The polypeptide may be used both in a solid as well as in a liquid formulation.
In some embodiments the invention relates to a method of reducing the formation of odor generating short chain fatty acids during lipid hydrolysis by employing the polypeptide.
The present invention is further described by the following examples which should not be construed as limiting the scope of the invention.
Chemicals used as buffers and substrates were commercial products of at least reagent grade.
A plasmid containing the gene encoding the polypeptide is constructed and transformed into a suitable host cell using standard methods of the art.
Fermentation is carried out as a fed-batch fermentation using a constant medium temperature of 34° C. and a start volume of 1.2 liter. The initial pH of the medium is set to 6.5. Once the pH has increased to 7.0 this value is maintained through addition of 10% H3PO4. The level of dissolved oxygen in the medium is controlled by varying the agitation rate and using a fixed aeration rate of 1.0 liter air per liter medium per minute. The feed addition rate is maintained at a constant level during the entire fed-batch phase.
The batch medium contains maltose syrup as carbon source, urea and yeast extract as nitrogen source and a mixture of trace metals and salts. The feed added continuously during the fed-batch phase contains maltose syrup as carbon source whereas yeast extract and urea is added in order to assure a sufficient supply of nitrogen.
Purification of the polypeptide may be done by use of standard methods known in the art, e.g. by filtering the fermentation supernatant and subsequent hydrophobic chromatography and ion exchange chromatography, e.g. as described in EP 0 851 913 EP, Example 3.
The activity of the lipase (LU) is determined as described above in the section Lipase activity. The absorbance of the lipase at 280 nm is measured (A280). The specific activity of a polypeptide may be expressed as the ratio of LU/A280.
The relative LU/A280 is calculated as the LU/A280 of the polypeptide divided by the LU/A280 of a reference enzyme. In the context of the present invention the reference enzyme is the lipase of SEQ ID NO:2 with the substitutions T231R+N233R.
Polypeptides of the present invention are tested using the Automatic Mechanical Stress Assay (AMSA). With the AMSA test the wash performance of a large quantity of small volume enzyme-detergent solutions can be examined. The AMSA plate has a number of slots for test solutions and a lid firmly squeezing the textile swatch to be washed against all the slot openings. During the washing time, the plate, test solutions, textile and lid are vigorously shaken to bring the test solution in contact with the textile and apply mechanical stress. For further description see WO 02/42740 especially the paragraph “Special method embodiments” at page 23-24. The containers, which contain the detergent test solution, consist of cylindrical holes (6 mm diameter, 10 mm depth) in a metal plate. The stained fabric (test material) lies on the top of the metal plate and is used as a lid and seal on the containers. Another metal plate lies on the top of the stained fabric to avoid any spillage from each container. The two metal plates together with the stained fabric are vibrated up and down at a frequency of 30 Hz with an amplitude of 2 mm.
Cream-turmeric swatches and coffee cream turmeric swatches were prepared by mixing 5 g of turmeric (Santa Maria, Denmark) with 10 g cream (38% fat, Arla, Denmark) and 100 g coffee cream (9% fat, Arla, Denmark) at 50° C., respectively. The mixture was left at this temperature for about 20 minutes and filtered (50° C.) to remove any un-dissolved particles. The mixture was cooled to 20° C. and woven cotton swatches, EMPA221, were immersed in the cream-turmeric mixture and afterwards allowed to dry at room temperature over night and frozen until use. The preparation of cream-turmeric swatches is disclosed in WO 06125437.
The performance of the polypeptide was measured as the brightness of the color of the textile samples washed with that specific polypeptide. Brightness can also be expressed as the intensity of the light reflected from the textile sample when illuminated with white light. When the textile is stained the intensity of the reflected light is lower, than that of a clean textile. Therefore the intensity of the reflected light can be used to measure wash performance of a polypeptide variant.
Color measurements were made with a professional flatbed scanner (PFU DL2400pro), which is used to capture an image of the washed textile samples. The scans were made with a resolution of 200 dpi and with an output color depth of 24 bits. In order to get accurate results, the scanner was frequently calibrated with a Kodak reflective IT8 target.
To extract a value for the light intensity from the scanned images, a special designed software application was used (Novozymes Color Vector Analyzer). The program retrieves the 24 bit pixel values from the image and converts them into values for red, green and blue (RGB). The intensity value (Int) is calculated by adding the RGB values together as vectors and then taking the length of the resulting vector:
Int=√{square root over (r2+g2+b2)}
The wash performance (P) of the polypeptides was calculated in accordance with the formula:
P=Int(v)−Int(r),
where Int(v) is the light intensity value of textile surface washed with enzyme, and Int(r) is the light intensity value of textile surface washed without enzyme.
A relative performance score is given as the result of the AMSA wash in accordance with the definition: Relative Performance scores (RP) are summing up the performances (P) of the tested polypeptide against the reference polypeptide:
RP=P(test polypeptide)/P(reference polypeptide).
RPavg indicates the average relative performance compared to the reference polypeptide of measurements done at 0.5 mg ep/l.
A polypeptide is considered to exhibit improved wash performance, if it performs better than the reference. In the context of the present invention the reference enzyme is the lipase of SEQ ID NO:2 with the substitutions T231R+N233R.
The butyric acid release from the lipase washed swatches were measured by Solid Phase Micro Extraction Gas Chromatography (SPME-GC) using the following method. Four pieces of textiles (5 mm in diameter), washed in the specified solution in Table 2 containing 0.5 mg/l lipase, were transferred to a Gas Chromatograph (GC) vial. The samples were incubated at 30° C. for 24 h and subsequently heated to 140° C. for 30 min and stored at 20° C.-25° C. for at least 4 h before analysis. The analysis was performed on a Varian 3800 GC equipped with a Stabilwax-DA w/Integra-Guard column (30 m, 0.32 mm ID and 0.25 micro-m df) and a Carboxen PDMS SPME fibre (85 micro-m). Sampling from each GC vial was done at 50° C. for 8 min with the SPME fibre in the head-space over the textile pieces and the sampled compounds were subsequently injected onto the column (injector temperature=250° C.). Column flow=2 ml Helium/min. Column oven temperature gradient: 0 min=50° C., 2 min=50° C., 6 min 45 s=240° C., 11 min 45 s=240° C. Detection was done using a Flame Ionization Detector (FID) and the retention time for butyric acid was identified using an authentic standard.
The risk performance odor (R) of a polypeptide is the ratio between the amount butyric acid released (peak area) from a polypeptide washed swatch and the amount butyric acid released (peak area) from a reference polypeptide washed swatch, after both values have been corrected for the amount of butyric acid released (peak area) from a non-polypeptide washed swatch (blank). The reference polypeptide is the polypeptide of SEQ ID NO: 2 with the substitutions T231R+N233R. The risk performance odor (R) of the polypeptide is calculated in accordance with the below formula:
Odor=measured butyric acid(peak area)released from the textile surface.
αtest enzyme=Odortest enzyme−Odorblank
αreference enzyme=Odorreference enzyme−Odorblank
R=α
test enzyme/αreference enzyme
A polypeptide is considered to exhibit reduced odor compared to the reference if the R factor is lower than 1.
The Benefit Risk factor describing the wash performance compared to the reduced risk for odor is thus defined as:
BR=RP
avg
/R
A variant is considered to exhibit improved wash performance and reduced odor, if the BR factor is higher than 1.
| Number | Date | Country | Kind |
|---|---|---|---|
| 08152163.5 | Feb 2008 | EP | regional |
This application claims priority or the benefit under 35 U.S.C. 119 of European application no. 08152163.5 filed Feb. 29, 2008 and U.S. provisional application No. 61/032,443 filed Feb. 29, 2008, the contents of which are fully incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61032443 | Feb 2008 | US |
