Patent Application
20130115671
This invention relates to a composition of enzymes comprising proteases, lipase, and carbohydrases from Conidiobolus brefeldianus, MTCC 5185. Further the invention relates to a process for preparation of said composition and uses thereof.
The current estimated value of worldwide sales of industrial enzymes is $1 billion. Of the industrial enzymes, 75% are hydrolytic. Proteases, amylases, lipases and xylanases together constitute around 85-90% total enzyme sales out of which proteases from plant, animal and microbial sources account for about 60%.
Bacterial proteases are well known, fungal source of proteases are limited though advantageous. Further fungal source of proteases in combination with other enzymes are also limited.
Conidiobolus coronatus has been known to be used as source for the production of alkaline proteases, refer U.S. Pat. No. 6,777,219, U.S. Pat. No. 7,186,546, “Optimization and scale up of production of alkaline protease from Conidiobolus coronatus”, by R. Seeta Laxman et. al; published in Process Biochemistry, Volume 40, Issue 9, Pages 3152-3158; dated September 2005, having doi:10.1016/j.procbio.2005.04.005 and “Thermostability of high-activity alkaline protease from Conidiobolus coronatus (NCL 86.8.20)” by S. H. Bhosale et. al; published in Enzyme and Microbial Technology 17:136-139, 1995. But there is no prior art for an enzyme composition that comprises proteases, lipases and carbohydrases from a strain of Conidiobolus species. U.S. Pat. No. 6,777,219 and U.S. Pat. No. 7,186,546 relate to processes for preparing alkaline proteases form Conidiobolus coronatus. Therefore the object of the invention is to provide an enzyme composition comprising of at least one enzyme selected from proteases, lipases, proteoglycanases, and carbohydrases from a fungal source, a hitherto unknown strain of Conidiobolus brefeldianus.
Another objective of the invention is to provide a process for preparation of an enzyme composition comprising of at least one enzyme selected from proteases, lipase, and carbohydrases using a fungal culture Conidiobolus brefeldianus isolated by the inventors.
Another objective of the present invention is to provide a process for the preparation of alkaline protease which is active and stable in wide pH range and in short fermentation cycles.
Still another objective of the present invention is to provide an economical process for the production of proteases, lipase, and carbohydrases alone or in combinations thereof. The object of the present invention is also to disclose the process of preparation of proteases, lipase, proteoglycanases, and carbohydrases alone or in combinations thereof on inexpensive media by a fungal culture belonging to the genus Conidiobolus brefeldianus isolated at National Chemical Laboratory, Pune, India.
Yet another objective of the invention is to provide methods of use of the enzymes of the invention in leather, detergent, food, textile, degumming of silk, production and recovery of serecin proteins/peptides from silk/silk wastes, animal tissue culture, analytical tools, pharmaceutical, cosmetics, molecular biology, and such like industries.
Accordingly, the present invention provides an enzyme composition comprising at least one enzyme selected from, but not limited to protease, lipase, carbohydrase, enzyme with hemagglutination activity and glycoprotein and degrading activity from a fungal source, a hitherto unknown strain of Conidiobolus brefeldianus MTCC-5185 is disclosed herein. The process of preparation of the enzyme composition and uses thereof are also disclosed. The enzyme composition of the invention comprises the enzymes disclosed herein alone or in combinations thereof.
The proteases of the invention are selected from, but not limited to alkaline proteases, proteases, elastase, keratinase, and peptidase, alone or in combinations thereof.
The carbohydrases of the invention are selected from, but not limited to glycosidases, particularly glycanases, more particularly chitinase, laminarinase, chondrotinase, alone or in combinations thereof.
The lipases of the invention comprise esterases.
In one embodiment, the invention relates to enzyme compositions comprising alkaline proteases that are active, stable over a wide pH range, stable to chemicals, temperature changes and have a shelf life as disclosed herein. The composition of the invention is stable to chemicals selected from, but not restricted to detergents, organic solvents, denaturants and similar compounds, having applications in leather, cosmetics, textile, food, detergent, pharmaceutical and other industries.
In one more embodiment of the invention, the enzymes composition is in the form of biomass
In another embodiment of the invention the enzyme composition comprises enzymes in crude form.
In another embodiment of the invention the enzyme composition comprises enzymes in purified form.
In another embodiment of the invention the enzyme composition comprises enzymes in refined form.
In yet another embodiment of the invention the enzyme composition comprises enzymes in free form.
In yet another embodiment of the invention the enzyme composition comprises enzymes in combination of free and immobilized form.
In yet another embodiment of the invention the enzyme composition comprises enzymes in immobilized form.
In yet another embodiment of the invention the enzyme composition comprises enzymes in cell bound form.
In another embodiment of the invention, the enzyme composition comprises enzymes in intra cellular form.
In yet another embodiment the present invention further provides a fermentation process for preparation of one or more enzymes selected from the group consisting of protease, carbohydrase and lipase either singly or simultaneously from Conidiobolus brefeldianus depending on the carbon, nitrogen and inducer used, wherein the said process comprising of:
In an embodiment of the process, the organism is grown in submerged culture with shaking at 180 to 220 rpm.
In another embodiment, the organism is grown in semi-solid culture under stationary conditions.
The carbon sources comprise of, but not restricted to sugars, sugar alcohols, polysaccharides, agricultural products, agricultural by products/wastes and such like, alone or in combinations thereof. The sugars are glucose, fructose, arabinose, sucrose, lactose and such like; sugar alcohols are glycerol, mannitol, sorbitol and such like; polysaccharides are starch and such like oils/fats are olive oil, sunflower oil, soyabean oil, gingelly oil, mustard oil, castor oil, coconut oil ground nut oil, tributyrin and such like and agricultural products/wastes are soya flour, soyabean meal, ground nut meal, mustard seed cake, cotton seed cake, wheat bran, rice bran and such like; chitin containing wastes like crab shells and such like.
The nitrogen source is optionally organic or inorganic, alone or in combinations thereof. The inorganic nitrogen sources are selected from, but not limited to di-ammonium hydrogen phosphate, ammonium sulphate, ammonium chloride, sodium nitrate, potassium nitrate and urea.
The organic nitrogen sources are selected from, but not limited to peptone, tryptone, soyatose, soyapeptone, casamino acids, casein, meat extract, beef extract, yeast extract, fish meal, feather meal, feathers, corn steep liquor and nitrogen-rich leguminous substrates exemplified by soya flour, soyameal, gram flour, mung flour, mustard seed cake, cotton seed cake, ground nut meal, wheat bran, rice bran and such like, wastes from dairy, poultry, meat and food processing, keratin rich wastes like hair, feathers, wastes from fisheries and other wastes, alone or in combinations thereof.
The conventional methods of separating enzymes are filtration, centrifugation or extraction with water or dilute surfactants. In an embodiment of the invention, the enzymes in intra cellular form re separated by including steps of cell breakage by sonication and mechanical grinding.
Carbon and nitrogen sources/inducers are selected from, but not limited to protein/nitrogen containing wastes from dairy like whey, food processing, meat and fish exemplified by fish meal and chicken feathers, feather meal and such like, or agricultural wastes, exemplified as oil seed cakes, and carbohydrate wastes like waste cereals/grains, oils, fats, tannery wastes like fleshings, trimmings and chrome shavings, keratin rich substrates like nails, hoofs, hair alone or in combinations thereof.
In an embodiment of the invention, the organic nitrogen sources are inducers for protease.
In a feature of the present invention, concentration of the enzymes was achieved either by membrane filtration or by salting out through addition of salts such as ammonium sulphate, sodium sulfate, sodium chloride, magnesium chloride etc., addition of organic solvents such as ethanol, acetone or by freeze drying or spray drying.
In a feature of the present invention, the lyophilized protease is stable at temperatures ranging from 4 to 40° C.
In a feature of the present invention, the spray dried protease is stable at temperatures ranging from 4 to 40° C. (760 days)
The protease of the invention is stable at pH range of 3-12, preferably pH 7, stable in presence of detergents, water miscible and water immiscible organic solvents, and stable up to 50° C. The protease is active in the pH range of 6-11, temperature range 30 to 60° C. and in presence of chelators, metal ions.
In an embodiment of the invention, the crude as well as partially purified protease show activity towards casein, albumin, haemoglobin, keratin, elastin-orcin, azocasein, azocoll, N-α-benzoyl-DL-arginine-p-nitroanilide (BAPNA) and gelatin.
In another embodiment of the invention, the protease was serine protease and inhibited by phenyl methyl sulphonyl fluoride (PMSF).
In an embodiment of the invention, lipase is active in the pH range of 4 to 9 preferably at pH 7 and temperature range of 20 to 60° C. preferably at 50° C.
In another embodiment of the invention, the enzyme composition is inert to true collagen.
In another embodiment of the invention, the protease is useful in degumming of silk and recovers serecin protein/peptides from degummed waste liquor.
The enzyme composition of the invention finds use in food, cosmetic, pharmaceutical, leather, textile industries, and resolution of optical isomers from racemic mixtures. Proteases find application in agriculture, leather, textile, degumming of silk, dairy, food, feed, detergent, pharmaceutical industries, animal tissue culture, silver removal from waste photographic films and nanoparticle synthesis, fertilizer, preparation of media ingredients and protein hydrolysates from plant, animal, peptide synthesis, in molecular biology, cosmetics, separation of racemic mixture of amino acids, waste treatment and such like. Keratinases find application in leather, detergent, prior degradation in mad cow disease and such like. Lipases find application in agriculture, leather, textile, dairy, food, feed, detergent, pharmaceutical industries, fertilizer, cosmetics, waste treatment, polymer synthesis and such like. Chitinases find application in agriculture. Chondrotinase finds application in spinal cord injury.
An enzyme composition comprising at least one enzyme selected from, but not limited to protease, lipase, carbohydrase enzyme with hemagglutination activity and glycoprotein degrading activity from a fungal source, a hitherto unknown strain of Conidiobolus brefeldianus MTCC-5185 is disclosed herein. The process of preparation of the enzyme composition and uses thereof are also disclosed. The enzyme composition of the invention comprises the enzymes disclosed herein alone or in combinations thereof.
The fungal strain, Conidiobolus brefeldianus is isolated from plant detritus and bears the accession number MTCC-5185 (Microbial Type Culture Collection, Chandigarh, India). The sources of Conidiobolus brefeldianus are soil, insect, leaf litter, tree twigs, and such like. FIG. 1 shows the microscopic picture of the fungal mycelia of Conidiobolus brefeldianus MTCC 5185 with protoplasmic contents and the thick walled zygospores with oil droplets. The
The proteases of the invention are selected from, but not limited to alkaline proteases, proteases, elastase, keratinase, and peptidase, alone or in combinations thereof.
The carbohydrases of the invention are selected from, but not limited to glycosidases, particularly glycanases, more particularly chitinase, laminarinase, chondrotinase, alone or in combinations thereof.
The lipases of the invention comprise esterases.
The determination of enzyme activity has been carried out by methods as described herein.
The reaction mixture contained an aliquot of suitably diluted enzyme solution and 10 mg Hammerstein casein in 0.1M sodium carbonate buffer pH 9.0 in a total volume of 2 ml. After incubation at 50° C. for 10 min, the reaction was terminated by the addition of 3 ml of 5% trichloroacetic acid (acidified with concentrated hydrochloric acid). The precipitate formed was filtered through Whatman No. 1 filter paper after standing for 30 min at room temperature. The absorbance of trichloroacetic acid soluble fraction was measured at 280 nm. Micrograms of tyrosine produced was calculated from a pre-calibrated graph of absorbance at 280 nm against tyrosine concentration and the units are expressed as μmoles of tyrosine released per minute under assay conditions.
The laminarinase (β-1,3 glucanase) activity was measured using 1% laminarin in 50 mM potassium phosphate buffer pH 7. The total reaction mixture of 1 ml contained 0.5 ml of suitably diluted enzyme and 0.5 ml substrate and incubated at 50° C. for 30 min. The reducing sugar liberated was measured by dinitro salicylic acid method (P. Bernfeld 1955, Amylase: a & β, Methods in Enzymology, Volume 1, 149). Laminarinase activity was expressed as μmoles of reducing sugar (as glucose equivalents) produced per min under the assay conditions.
Lipase activity was measured by two different methods.
a. Spectrophotometric assay using p-nitro phenol butyrate (pNPB) as substrate: 30 mg pNPB was dissolved in 10 ml of isopropanol and 0.1 ml Triton-X-100 and volume made to 100 ml with 50 mM phosphate buffer, pH 7. The assay mixture contained 0.9 ml substrate and 0.1 ml suitably diluted enzyme. The assay mixture was incubated at 50° C. for 30 min and terminated by addition of 2 ml of isopropanol. The amount of p-nitrophenol released was measured at 410 nm. The lipase activity is expressed as moles of p-nitro phenol released per 30 min under the assay conditions.
b. Titrimetric assay of Lipase: The substrate was prepared by mixing 20 ml of olive oil, 165 ml of 10% gum arabic and 15 g ice in grinder mixer for 10 minutes and filtered on glass wool and stored at 4° C. For lipase assay the reaction mixture contained 2 ml phosphate buffer (50 mM, pH 7.0), 5 ml substrate and 1 ml crude culture broth and incubated at 50° C. for 1 h with shaking at 50 rpm. The reaction was terminated by addition of 4 ml of acetone:ethanol (1:1). In blank the enzyme was added after the termination of reaction by acetone:ethanol. Free fatty acids released were titrated with 10 mM NaOH. The lipase activity is expressed as μmoles of free fatty acids released per min under the assay conditions.
Chitinase assay was measured using 0.7% chitin. Reaction mixture contained 1 ml of enzyme, 1 ml of 50 mM acetate buffer, pH 5 and 1 ml of 0.7% chitin as substrate. The reaction mixture was incubated at 50° C. for 1 h. The N-acetylglucosamine liberated was estimated by measuring the absorbance at 585 nm spectrometrically with p-dimethyl amino benzaldehyde. One unit of activity is defined as the amount of enzyme required to liberate 1 μmole of N-acetyl glucosamine per minute under the assay conditions.
Chondroitinase activity was measured by spectrophotometric method at 37° C. Appropriately diluted enzyme (0.8 ml) was equilibrated at 37° C. for 10 min after which 0.2 ml of 0.5% Chondroitin sulphate A in 0.05% bovine serum albumin prepared in 250 mM Tris HCl and 300 mM sodium acetate buffer, pH 8 was added and mixed immediately. The reaction mixture was incubated at 37° C. up to 21 min. Aliquots of 0.1 ml were withdrawn at an interval of 3 min and transferred to tubes containing 0.9 ml of 50 mM KCl adjusted to pH 8 and incubation continued at 37° C. for another 10 min. At the end of 10 min, the contents were centrifuged and absorbance was measured at 232 nm. Absorbance at zero minute served as blank for the assay. Activity was calculated from the slope (increase in absorbance/per min) of the liner portion of the graph of absorbance against time as shown below. One unit is defined as the amount of enzyme required to liberate one micromole of 2-acetamido-2-deoxy-3-O-(β-D-gluc-4-ene-pyranosyluronic acid)-4-O-sulfo-D-galactose from chondroitin sulfate A per minute under the assay conditions.
where 5.1 is the milli molar extinction coefficient of unsaturated disaccharides for chondroitin sulfate A
Traditionally, keratinases have been used for production of feather meal, fertilizers and glues etc. Their application range is slowly widening and now they are increasingly being used in to other areas such as detergent formulation, cosmetics, leather, medicine and animal feed. More recently, they find applications in treatment of mad cow disease (degradation of prion), biodegradable plastic and feather meal production. Application of keratinases having mild elastolytic activity but lacking collaginolytic is being explored for the dehairing process in leather manufacture. Skins and hides contain substantial quantities of valuable GAGs (0.2-0.3% on raw weight. An enzyme composition comprising of lipase, keratinase, chondrotinase and chitinase will be useful dehairing.
The enzyme composition of the invention finds use in food, cosmetic, pharmaceutical, leather, textile industries, and resolution of optical isomers from racemic mixtures. Proteases find application in agriculture, leather, textile, degumming of silk, dairy, food, feed, detergent, pharmaceutical industries, animal tissue culture, silver removal from waste photographic films and nanoparticle synthesis, fertilizer, preparation of media ingredients and protein hydrolysates from plant, animal, peptide synthesis, in molecular biology, cosmetics, separation of racemic mixture of amino acids, waste treatment and such like. Keratinases find application in leather, detergent, prior degradation in mad cow disease and such like. Lipases find application in agriculture, leather, textile, dairy, food, feed, detergent, pharmaceutical industries, fertilizer, cosmetics, waste treatment, polymer synthesis and such like. Chitinases find application in agriculture. Chondrotinase finds application in spinal cord injury.
The present invention is described herein below with examples, which are illustrative only and should not be construed to limit the scope of the present invention in any manner whatsoever.
The present invention is described herein below with examples, which are illustrative only and should not be construed to limit the scope of the present invention in any manner whatsoever.
This example illustrates the isolation of the Conidiobolus brefeldianus MTCC 5185 and its identification by morphological characteristics. The fungal culture was isolated from decomposing plant detritus collected from Pune, Maharashtra, India. Fine particles of plant detritus were superimposed on MGYP agar (malt extract-0.3%; yeast extract-0.3%; peptone-0.5%, gluscose-1%, agar-2%) blocks attached to the inner surface of the petri plate lid and plates were incubated at 28° C. Isolated single colonies developing from forcibly discharged conidia were picked up and transferred to MGYP agar slants, incubated at 28° C. for 2-3 days. The organism grows rapidly and was identified as a strain belonging to genus Conidiobolus on the basis of the morphology of the forcibly discharged large globose conidia with basal papillae. Mycelium is coenocytic but becomes septate in later stages. Conidiophores are micronemous and indistinguishable from mycelium. At the tip of the conidiophore, large globose conidia are formed which are discharged forcibly. The size of conidia varies between 35-45 microns. Conidia either germinate to give rise to mycelium or to microconidia on radial sterigmata or to succession of secondary conidia. The discharged conidia are visible as whitish/creamish deposit on the glass above the growing culture. The organism is zygosporic and the zygospores (resting spores) are round, smooth and thick walled with 2 distinct wall layers and granular contents inside (
This example illustrates the isolation of genomic DNA of Conidiobolus brefeldianus MTCC 5185 by cetyl trimethyl ammonium bromide (CTAB) method. For isolation of DNA, the fungus was grown in liquid flasks in malt extract glucose yeast extract peptone (MGYP) medium the composition of which is (g/L) malt extract-3; yeast extract-3; peptone-5 and glucose-10. Growth was initiated by inoculating spores from a 7 days old MGYP slant. The flasks were incubated on a rotary shaker (200 rpm) for 48 hours at 28° C. The contents were centrifuged at 8000 rpm for 15 min, washed repeatedly to remove the media constituents. 3-5 g of wet mycelium was ground in liquid nitrogen, followed by addition of 8-10 ml of CTAB extraction buffer, pH 8 containing 0.2% β-mercaptoethanol after which 20 μl of proteinase K (20 mg/ml) was added and incubated at 65° C. for 1 h. This was followed by addition of 20 μl RNase A (10 mg/ml) and further incubation at 65° C. for 15 min. To the supernatant collected after centrifugation (8000 rpm, 10 min), 10 ml chloroform:isoamylalcohol (24:1) was added. The mixture was shaken for 5 min and centrifuged at 10,000 rpm, 4° C. for 15 min. Two volumes of CTAB precipitation buffer, was added to the supernatant and kept at room temperature for 1 h. The pellet collected after centrifugation was dissolved in 5 ml of 1.2 M NaCl and 5 ml of chloroform:isoamylalcohol (24:1) was added. Two volumes of absolute alcohol were added to the aqueous phase to precipitate the DNA. DNA was spooled out and washed with 70% ethanol and dissolved in 5 ml of 0.1M Tris EDTA buffer pH 8.0 and stored. The quantification of DNA was done by measuring the absorbance of the sample at 260 nm on spectrophotometer and purity was checked on 0.8% agarose gel electrophoresis.
This example illustrates the polymerase chain reaction (PCR) amplification of genomic DNA for 18S rDNA gene. The primers used for the identification of fungal species were universal fungal 18S ribosomal DNA (rDNA) primers NS1-F (GTA GTC ATA TGC TTG TCT C), NS8-R (TCC GCA GGT TCA CCT ACG GA). The polymerase chain reaction (25 μl) was set to amplify the 18S rDNA gene by using the genomic DNA. The reaction mixture typically contained genomic DNA-0.70 μl, 10×PCR Buffer-2.50 μl, 0.2 mM dNTPs-2.5 μl, forward and reverse primers 10-20 pmoles-1.25 μl each, distilled water-16.60 μl, and 1 unit of Taq DNA polymerse-0.20 μl. The PCR conditions for 18S rDNA gene amplification were: initial denaturation-95° C. for 3 min; followed by 35 cycles of 94° C. for 1 min, 57° C. for 30 sec, 72° C. for 2 min and final extension at 72° C. for 10 min. 5 μl of the above PCR amplified product was used to check the amplification on 1.0% agarose gel.
This example illustrates the purification of PCR amplified products. To 20 μl PCR amplified products, 12 μl of 20% PEG-NaCl (Polyethylene glycol-NaCl) solution was added and incubated at 37° C. for 30 min. It was then centrifuged at 12,000 rpm for 20 min. The supernatant was discarded and the pellet was washed twice with 70% ethanol and separated by centrifuging at 12,000 rpm for 20 min. The pellet was dried and dissolved in 10 μl of double distilled water and stored at −20° C.
This example illustrates the sequencing of the purified PCR products. The sequencing reactions were carried out using Taq DNA polymerase using the ‘ABI PRISM BigDye Terminator Cycle Sequencing Ready Reaction Kit’ (Perkin Elmer Applied Biosystems Division, Foster City, Calif.) according to the manufacturer's protocol. This Kit contains the four ddNTPs with different fluorescence labels termed as BigDye Terminators. 41 PCR product and 3 pmol of the sequencing primer were used in a 20 μl sequencing reaction. The sequencing primers were NS1 (GTA GTC ATA TGC TTG TCT C), NS2 (GGC TGC TGG CAC CAG ACT TGC), NS3 (GCA AGT CTG GTG CCA GCA GCC), NS4 (CTT CCG TCA ATT CCT TTA AG), NS5 (AAC TTA AAG GAA TTG ACG GAA G), NS6 (GCA TCA CAG ACC TGT TAT TGC CTC), NS7 (GAG GCA ATA ACA GGT CTG TGA TGC) and NS8 (TCC GCA GGT TCA CCT ACG GA) for sequencing (White et al 1990). The sequencing reaction mixes were subjected to 25 cycles in a Perkin Elmer thermal cycler 9700. Each cycle consisted of 95° C. for 10 min, 50° C. for 5 min and 60° C. for 4 min. DNA sequencing was carried out on ABI 1500 Automated Sequencer.
This example illustrates the identification and phylogenetic relationship of new strain of Conidiobolus sp MTCC 5185 on the basis of 18S rDNA sequence obtained in above example. The sequences obtained were in small fragments and hence it was aligned properly by overlapping the sequences. Percentage homology and phylogenetic relationship of new strain of Conidiobolus sp using obtained sequences of 18S rDNA were done in NCBI database. The nucleotide sequence was analyzed with the GenBank database using Basic Local Alignment Search Tool (BLAST) program (www.ncbi.ncm.gov/blast). The result in the Table 1 shows the first 10 BLAST hit of 18S rDNA sequence in NCBI database. 18S rDNA showed maximum (99%) sequence homology with one strain of Conidiobolus brefeldianus AF 368506.1. The 18S rDNA sequence of MTCC 5185, a new strain of Conidiobolus brefeldianus has been deposited in NCBI gene bank with the accession number FJ895304. The
Conidiobolus brefeldianus small subunit ribosomal RNA
Conidiobolus coronatus strain NRRL1912 18S ribosomal
Conidiobolus coronatus gene for 18S rRNA
Conidiobolus coronatus small subunit ribosomal RNA
Conidiobolus firmipilleus small subunit ribosomal RNA
Conidiobolus coronatus strain NRRL28638 18S
Conidiobolus incongruus 18S ribosomal RNA gene,
Conidiobolus coronatus strain ARSEF 206 18S ribosomal
Conidiobolus rhysosporus small subunit ribosomal RNA
Conidiobolus pumilus small subunit ribosomal RNA
This example illustrates the preparation of the protease by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Fermentation was carried out in shake flasks in a medium containing (grams per liter) Glucose-20; Yeast extract-3, Soyabean meal-30. Spores from a 3 days old MGYP slant were used for preparing the seed culture, the composition of which is (grams per liter) Glucose-10; Yeast extract-3. This was incubated on a rotary shaker for 24 hours at 28° C. and was used to initiate the shake flask experiments. The shake flask experiment was run for 72 h at 28° C. on a rotary shaker (200 rpm). Protease activity was estimated according to Laxman et al (2005), Process Biochemistry, Volume 40, 3152-3158 (2005). One unit of activity is defined as the amount of enzyme required to release one micromole of Tyr/min. The protease activity in the cell free broth after 3 days was 36-38 IU/ml.
This example illustrates the preparation of the protease by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Fermentation was carried out in shake flasks in a medium containing (grams per liter) Glucose-20; Di-ammonium hydrogen phosphate−1.6, Soybean meal-30. Spores from a 3 days old MGYP slant were used for preparing the seed culture, the composition of which is (grams per liter) Glucose-10; Yeast extract-3; Peptone-5. This was incubated on a rotary shaker for 24 hours at 28° C. and was used to initiate the shake flask experiments. The shake flask experiment was run for 72 h at 28° C. on a rotary shaker (200 rpm). The activity in the cell free broth after 3 days was 34-40 IU/ml.
This example illustrates the preparation of the protease by submerged fermentation in an instrumented fermentor under controlled conditions of agitation and aeration using the strain Conidiobolus brefeldianus MTCC 5185. Fermentation was carried out in 7.5 L New Bruinswick fermentor with 5 L working volume. Spores from 3 days old MGYP plate/slant were used to develop the inoculum in 1 L flasks containing 250 ml medium the composition of which is (grams per liter) yeast extract-3; peptone-5 and glucose-10 (GYEP) and incubated for 24 h at 28° C., 220 rpm. The fermentor was inoculated with 500 ml (10% v/v) of 24 h vegetative inoculum. The production medium (4.5 L) in 7.5 L fermentor contained 2% commercial grade glucose, 0.3% yeast extract as a basal medium. Soyabean meal at a concentration of 3% was used as an inducer. Aeration and stirrer speed were kept at 3-4 rpm and 350-400 rpm respectively and temperature was maintained at 26-28° C. The activity in the cell free broth after 2-3 days was 36-40 IU/ml.
This example illustrates the preparation of the protease by submerged fermentation in an instrumented fermentor under controlled conditions of agitation and aeration using the strain Conidiobolus brefeldianus MTCC 5185. Fermentation was carried out in 75 L fermentor with 50 L working volume. Following fermentation parameters were followed for production: 3 days old MGYP slant as stock; 15 h old pre-inoculum grown in medium the composition of which is (grams per liter) yeast extract-3; peptone-5 and glucose-10 (GYEP); 15 h old inoculum grown in medium the composition of which is (grams per liter) yeast extract-3 and glucose-10 (GYE); production medium containing 2% commercial glucose, 0.16% fertilizer grade di-ammonium hydrogen phosphate (DAP) and 3% Soyabean meal (SBM). Initially, SBM along with antifoam were sterilized at 121° C. for 30 min. After cooling, glucose and DAP were added and re-sterilized for 20 min and kept under positive pressure until inoculation. Temperature was maintained at 28-30° C. throughout the fermentation. Agitation was kept initially at 80 rpm and increased slowly to a maximum of 120 rpm at the end the fermentation. Aeration was kept initially at 0.8 vvm and increased to 1.2-1.4 vvm after 36 h. The activity in the cell free broth after 2-3 days was 36-40 IU/ml.
This example illustrates the detection of lipase activity secreted by Conidiobolus brefeldianus MTCC 5185 using plate assay. Plate assay for enzyme was carried out in disposable petri-plate containing 25 ml Mikami medium which was composed of (grams per liter): glucose-1.5; yeast extract-1.5; peptone-5; beef extract-5, agar-20 and 1% emulsified tributyrin. Spore suspension from a 2 day old slant was used for preparing the GYE inoculum whose composition was (grams per liter): yeast extract-3 and glucose-10. After 24 hours of growth, one loopful of growth was spot inoculated on the plate and incubated at 28° C. for 72 h. A zone of clearance around the growing fungal colonies due to the degradation of tributyrin was observed indicating secretion of lipase by the organism (
This example illustrates the detection of chitinase activity using plate assay by the strain Conidiobolus brefeldianus MTCC 5185. Plate assay was carried out in 25 ml of 2% agar containing 0.01% acid swollen chitin in disposable petri-plate. Spores from a 3 day old slant were inoculated in the production medium the composition of which is (grams per liter): yeast extract-3; glucose-10 and acid swollen chitin-0.1 and incubated at 28° C. with shaking at 180-200 rpm. Samples were removed after 24, 48 and 72 h and 50 μl of cell free supernatant was added in the wells made on the plate and incubated at 37° C. for 1 h. For detection of chitinase activity, the plate was flooded with 0.1% ranipal for 15 min followed by washing twice with distilled water for 30 min each. The plate was observed under UV light. A light blue clear zone around the sample spot was observed due to chitin degradation indicating secretion of chitinase by the fungal strain (
This example illustrates the detection of chondroitinase activity secreted by the strain Conidiobolus brefeldianus MTCC 5185 using plate assay. Plate assay for enzyme was carried out in disposable petri-plate containing MGYP agar medium supplemented with bovine serum albumin (BSA) and Chondroitin sulphate A. Malt extract-0.15 g; yeast extract-0.15 g; peptone-0.25 g; glucose-0.5 g were dissolved in 40 ml distilled water, 1 g agar was added and autoclaved. BSA (500 mg) and Chondroitin sulphate A (20 mg) were dissolved in 10 ml distilled water and filter sterilized and added to the medium and poured in sterile petri plates. Spore suspension from a 2 day old slant was used to inoculate GYE medium whose composition was (grams per liter): yeast extract-3 and glucose-10. After 24 hours of growth, 10% (v/v) vegetative growth was transferred to the medium containing (grams per liter): glucose-20; diammonium hydrogen phosphate-1.6; soyabean meal-30 and incubated at 28° C., 180 rpm. After 48 h, one loopful of growth was spot inoculated on the plate and incubated at 28° C. After four days, the plate was flooded with 2N acetic acid and allowed to stand for 15 minutes at room temperature. Un-degraded chondroitin sulphate A conjugated with BSA giving opaque appearance while a zone of clearance around the colony was seen indicating the secretion of chondrotinase leading to hydrolysis of chondroitin sulphate A. (
This example illustrates the preparation of the lipase by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Spore suspension from a 2 day old slant was used for preparing the glucose yeast extract seed culture, the composition of which is (grams per liter): yeast extract-3, glucose-10. This was incubated on a rotary shaker at 28° C. for 24 hours and was used to initiate the shake flask experiments. Fermentation was carried out in shake flasks in Mikami medium containing (grams per liter): peptone-5; beef extract-5; yeast extract-1.5; glucose-1.5. Olive oil at 2% concentration was used as inducer for lipase production. Medium was adjusted to pH 7. Lipase activities in the cell free broth after 3 days were determined spectrophotometric method using p-nitrophenyl butyrate as substrate and activities were in the range of 0.5-0.6 IU/ml.
This example illustrates the inductive effect of various oils and fats on production of the lipase by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Spore suspension from a 2 day old slant was used for preparing the glucose yeast extract seed culture, the composition of which is (grams per liter): yeast extract-3, glucose-10. This was incubated on a rotary shaker at 28° C. for 24 hours and was used to initiate the shake flask experiments. Fermentation was carried out in shake flasks in Mikami medium containing (grams per liter): peptone-5; beef extract-5; yeast extract-1.5; glucose-1.5. Following oils at 2% concentration were used as inducers for lipase production: soyabean oil; olive oil, sunflower oil and tributyrin. Medium was adjusted to pH 7. Lipase activities in the cell free broth after 4 days were determined by titrimetric method. Lipase activities in soyabean; olive and sunflower oils ranged between 0.41-0.43 U/ml while tributyrin gave higher activities of 0.63 U/ml.
This example illustrates the preparation of the protease and lipase by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Spore suspension from a 2 day old slant was used for inoculating the fermentation medium whose composition is (grams per liter): Malt extract-3; peptone-5, glucose-10; yeast extract-3. Medium was adjusted to pH 7. Soyabean meal (2%) and soyabean oil (1%) were used as inducers for protease and lipase production respectively. Protease and lipase activities in the cell free broth after 3 days were determined by caseinolytic and titrimetric methods respectively. Protease and lipase activities were in the range of 12-15 IU/ml and 1-1.2 IU/ml respectively.
This example illustrates the preparation of the chitinase by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Spore suspension from a 3 day old slant was used for preparing the glucose yeast extract seed culture, the composition of which is (grams per liter): yeast extract-3, glucose-10. This was incubated on a rotary shaker at 28° C. for 24 hours and was used to initiate the shake flask experiments. Fermentation was carried out in shake flasks in Mikami medium containing (grams per liter): peptone-5; beef extract-5; yeast extract-1.5; glucose-1.5. Chitin at 1% concentration was used as inducer for chitinase production. Medium was adjusted to pH 7. Chitinase activities in the cell free broth after 2 and 3 days were 0.011 IU/ml and 0.016 IU/ml respectively.
This example illustrates the preparation of protease and chitinase by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Spore suspension from a 3 day old slant was used for preparing the glucose yeast extract seed culture, the composition of which is (grams per liter): yeast extract-3, glucose-10. This was incubated on a rotary shaker at 28° C. for 24 hours and was used to initiate the shake flask experiments. Fermentation was carried out in shake flasks in medium containing (grams per liter): glucose-20; chitin-0.1; di-ammonium hydrogen phosphate-1.6. Medium was adjusted to pH 7 and soyabean meal was added as inducer at 3% concentration. Protease and chitinase activities in the cell free broth after 2 days were 25-29 IU/ml and 0.014-0.016 IU/ml respectively.
This example illustrates the preparation of protease and laminarinase by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Spore suspension from a 3 day old slant was used for preparing the glucose yeast extract seed culture, the composition of which is (grams per liter): yeast extract-3, glucose-10. This was incubated on a rotary shaker at 28° C. for 24 hours and was used to initiate the shake flask experiments. Fermentation was carried out in shake flasks in medium containing (grams per liter): glucose-20; di-ammonium hydrogen phosphate-1.6. Medium was adjusted to pH 7 and soyabean meal was added as inducer at 3% concentration. Protease and laminarinase activities in the cell free broth after 2 days were 26-28 IU/ml and 0.95-1.21 IU/ml respectively.
This example illustrates the preparation of protease and keratinase by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Spore suspension from a 2 day old slant was used for preparing the glucose yeast extract seed culture, the composition of which is (grams per liter): yeast extract-3, glucose-10. This was incubated on a rotary shaker at 28° C. for 24 hours and was used to initiate the shake flask experiments. Fermentation was carried out in shake flasks in Mikami medium containing (grams per liter): peptone-5; beef extract-5; yeast extract-1.5; glucose-1.5. Medium was adjusted to pH 7 and chicken feathers (1%) were added separately to each flask as inducer for keratinase. The shake flasks were incubated for 48 h at 28° C. on a rotary shaker (200 rpm). Keratinase activity was determined according to Bressollier et al, (Applied Environmental Microbiology, Vol. 65 (6), 2570-2576, 1999. One unit of enzyme activity is defined as the amount of enzyme required to cause an increase in absorbance by 0.01 at 595 nm per min. Protease activities in the cell free broth after 24 and 48 h were 3.34 IU/ml and 7.90 IU/ml respectively. Keratinase activities for 24 and 48 h were 150.02 and 252.45 U/ml respectively.
This example illustrates the preparation of the protease and chondroitinase by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Amicon concentrated enzyme sample as described in example 28 showed protease and chondroitinase activities of 222.12 U/ml and 0.1-0.16 U/ml respectively
This example illustrates the preparation of the protease using various carbon sources by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Spores from a 2 days old MGYP slant were used for preparing the seed culture, the composition of which is (grams per liter) Glucose-10; Yeast extract-3. This was incubated on a rotary shaker for 24 hours at 28° C. and was used to initiate the shake flask experiments. Fermentation was carried out in shake flasks in a medium containing (grams per liter) carbon source-10; Yeast extract-3, Soyabean meal-30. Fructose, glucose, glycerol, lactose, mannitol and starch at 1% concentration were used as carbon sources. The shake flasks were incubated at 28° C. for 72 h on a rotary shaker (200 rpm). The activities for 48 h samples are presented in accompanying Table 2 and forming the part of this specification. Glucose was found to be the best carbon source.
This example illustrates effect of inducers on the preparation of the protease by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Spores from a 3 days old MGYP slant were used for preparing the seed culture, the composition of which is (grams per liter): glucose-10; yeast extract-3. This was incubated on a rotary shaker for 24 hours at 28° C. and was used to initiate the shake flask experiments. Fermentation was carried out in shake flasks in a medium containing (grams per liter): glucose-10; yeast extract-3, inducer-20. Following inducers were used: soyabean meal, cotton seed cake, mustard seed cake, groundnut cake, gram flour, mung dal flour, soyatose, skim milk, tryptone, casein and casamino acids. The shake flasks were incubated at 28° C. for 72 h on a rotary shaker (200 rpm). The activities for 48 h samples are presented in accompanying Table 3 and forming the part of this specification. All the inducers tested induced protease production.
This example illustrates the preparation of the protease using different concentrations of soyabean meal as inducer by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Spores from a 2 days old MGYP slant were used for preparing the seed culture, the composition of which is (grams per liter) Glucose-10; Yeast extract-3. This was incubated on a rotary shaker for 24 hours at 28° C. and was used to initiate the shake flask experiments. Fermentation was carried out in shake flasks in a medium containing (grams per liter): glucose-10; Yeast extract-3, Soyabean meal −0; 10; 20; 30; 40; 50. The shake flasks were incubated at 28° C. for 72 h on a rotary shaker (200 rpm). The activities for 48 h samples are presented in accompanying Table 4 and forming the part of this specification.
This example illustrates protease production in the temperature range of 20 to 45° C. by submerged fermentation using the strain Conidiobolus brefeldianus MTCC 5185. Spore suspension from a 3 day old slant was used for preparing the MGYP seed culture, the composition of which is (grams per liter): malt extract-3; yeast extract-3; peptone-5 and glucose-10. This was incubated on a rotary shaker at 28° C. for 24 hours and was used to initiate the shake flask experiments. Production was carried out in shake flasks in MGYP liquid medium containing (grams per liter): malt extract-3; yeast extract-3; peptone-5 and glucose-10, soyabean meal-20 and adjusted to pH 6.5-7. The flasks were incubated at temperatures ranging from 20 to 45° C. on a rotary shaker (200 rpm) for 48 h. Protease production was observed in the temperature range of 20 to 37° C. with highest activities at 28° C. (Table 5).
This example illustrates the preparation of the protease by submerged fermentation in the pH range 5 to 10 using the strain Conidiobolus brefeldianus MTCC 5185. Spore suspension from a 3 day old slant was used for preparing the GYE seed culture, the composition of which is (grams per liter): yeast extract-3 and glucose-10. This was incubated on a rotary shaker at 28° C. for 24 hours and was used to initiate the shake flask experiments. Fermentation was carried out in shake flasks in a medium containing (grams per liter): glucose-20; yeast extract-3, soyabean meal-20. Medium pH was varied from pH 5 to 10 by addition of sterile NaOH or HCl. The shake flasks were incubated at 28° C. on a rotary shaker (200 rpm) for 48 h. Protease production was observed in the pH range 5 to 10 (Table 6).
Conidiobolus brefeldianus MTCC 5185
This example illustrates the pH range in which the protease secreted by the said strain is active. For determination of optimum pH for protease, the enzyme was diluted and assayed in buffers of different pH ranging from 5 to 12. Following buffers at 0.1M concentration were used: Acetate (pH 5), sodium phosphate buffer (pH 6, 7), Tris HCl buffer (pH 8) and carbonate bicarbonate (pH 9 and 10), sodium phosphate-NaOH (pH 11, 12) and KCl-NaOH (pH 12.0). The results are presented in accompanying Table 7 and forming the part of this specification. It is observed that the enzyme is active between pH 6 and 11.
This example illustrates the temperature range in which the protease secreted by the said strain is active. For determination of optimum temperature, protease activity was determined with carbonate bicarbonate buffer (0.1M, pH 9) at temperatures ranging from 30 to 70° C. The results of the experiment have been illustrated in Table 8 accompanying and forming the part of this specification. It is observed that the enzyme is active between 30 to 60° C.
Stability of the said protease at 40° C. with respect to time was determined by incubating the crude protease in phosphate buffer pH 7.0 at 40° C. up to 2 h. The crude protease was produced as described in example 4 Aliquots were removed at regular intervals of 15 min and residual activity was estimated at 50° C., pH 9. The results are illustrated in Table 9 wherein the protease was stable up to 2 h at 40° C. and retained approximately 60% activity.
This example illustrates the concentration of protease by lyophilization. The protease (100 ml) produced as described in example 4 and having 36.33 U/ml activity was lyophilized for 6 hours (−55° C.) till liquid completely evaporated leaving dry hygroscopic powder. The lyophilized powder was dissolved in deionozed water and protease activity was estimated. Lyophilized sample showed an activity of 191.88 U/ml. Recovery of protease was found to be above 95%. This indicates that the protease stable to lyophilization.
This example illustrates the concentration of protease by ultrafiltration. Protease produced as described in example 4 was centrifuged at 10,000 rpm. The clear supernatant (1200 ml) having activity of 25.84 IU/ml was concentrated in Amicon membrane filtration unit on YM-3 membrane with a molecular weight cut off of 3,000 daltons. Volume after concentration was 150 ml with 206.72 IU/ml protease activity. The recovery after filtration was 95-98%. In another set 1000 ml of supernatant was also concentrated on PM-10 membrane (10,000 daltons cut off) to 100 ml with 85% recovery.
This example illustrates the concentration of protease by ammonium sulphate precipitation with 90% saturation. Protease produced as described in example 6 was centrifuged at 10,000 rpm. The clear supernatant (1000 ml) having activity of 31.29 IU/ml was used for concentration. Precipitation was carried out at 4° C. by adding 600 g of ammonium sulphate with slow continuous mixing. Stirring was continued for another 2 h for complete precipitation and allowed to settle in cold. The clear supernatant was decanted and the volume of the suspension was reduced to 250 ml resulting in 4 fold concentration of protease. The protease activity in the suspension was estimated after dissolving the precipitate obtained after centrifugation at 10,000 rpm in the 10 mM Tris HCl buffer, pH 8. There was more than 90% recovery of protease and the activity in the suspension was 118.12 IU/ml.
This example illustrates the stability of protease from Conidiobolus brefeldianus MTCC 5185 in presence of detergents. The crude protease produced as described in example 4 was incubated with 0.7 mg/ml detergents (final concentration) at 40° C. up to 1 h. Samples were removed at intervals of 15 min and residual activity was measured and expressed as percentage of initial activity with respective detergents taken as 100%. The protease was stable in the presence of all detergents and retained 75-94% activity after 15 minutes depending on the detergent (Table 10). Even after 1 h, around 35-50% activity was retained.
This example illustrates that the protease secreted by Conidiobolus brefeldianus MTCC 5185 is active in presence of various metals. The crude protease produced as described in example 4 was used. Protease activity was estimated in presence of metals. Stock solutions of metals (100 mM) were prepared and added to the assay mixture at final concentration of 5 mM. The results of the experiment have been illustrated in Table 11 accompanying and forming the part of this specification. Protease was active in presence of Ca, Cd, Co, K, Mg and Mn while Ni and Zn resulted in 35-40% inhibition. Cu and Hg totally inhibited the protease activity.
This example illustrates the temperature range in which the protease secreted by the said strain is stable for 1 h. For determining the temperature stability, crude ultrafiltered protease as described in example 27 was incubated at temperatures ranging from 4 to 70° C. for 1 h and the residual activity was measured at 50° C., pH 9. The results are illustrated in Table 12 wherein it is observed that the enzyme is stable up to 50° C.
This example illustrates the stability of protease at 50° C. Stability of three different samples of the said protease at 50° C. with respect to time was determined by incubating the protease at 50° C. up to 2 h. The crude culture filtrate, ammonium sulphate precipitate and ultrafiltered (membrane) protease samples as described in examples 4, 27 and 28 were used for stability studies. Aliquots were removed at regular intervals of 30 min and residual activity was estimated at 50° C., pH 9. The results are illustrated in Table 13 wherein all the protease samples retained more than 60% activity at 50° C. after 30 min. Ammonium sulphate precipitated sample was found to be more stable which retained around 40% activity after 2 h while culture filtrate and PM-10 Retentate retained around 25-27% activity after 2 h.
This example illustrates the stability of the protease in presence of sugar alcohols. Ultrafiltered protease as described in example 27 was incubated at 50° C. in presence of glycerol, mannitol, sorbitol and xylitol at 20% concentration up to 3 h. Aliquots were removed at regular intervals of 30 min and residual activity was estimated at 50° C., pH 9. The results are illustrated in Table 14. All the sugar alcohols increased the stability of enzyme and more than 30% activity was retained after 3 h. Among them, sorbitol offered greater thermostability to the protease with 47% residual activity.
This example illustrates the stability of the protease in presence of sorbitol and trehalose. Ultrafiltered protease as described in example 27 was incubated at 50° C. in presence of 20, 40 and 50% sorbitol and trehalose up to 4 h. Aliquots were removed at regular intervals of 60 min and residual activity was estimated at 50° C., pH 9. The results are illustrated in Table 15. Stability increased with increasing concentration of trehalose and sorbitol. There was nearly 5 to 6 fold increase in thermostability with 50% sorbitol and trehalose which retained nearly 80% activity even after 4 h while control without additives showed 12.67% residual activity.
This example illustrates the stability of the protease in presence of salts. Ultrafiltered protease as described in example 27 was incubated at 50° C. in presence of 10 mM CaCl2, 0.5M NaCl, 0.5M glycine and 15% Ammonium sulphate up to 3 h. Aliquots were removed at regular intervals of 30 min and residual activity was estimated at 50° C., pH 9. The results are illustrated in Table 16. Stability increased in presence of all the salts. Calcium chloride and ammonium sulphate offered greater protection to thermal denaturation where the residual activity was around 55% after 3 h while control showed around 20% residual activity.
This example illustrates the effect of water miscible as well as water immiscible organic solvents on stability of crude protease at 28° C. Following organic solvents were used: acetone, acetonitrile, 1-butanol, dimethylsulphoxide, isopropanol and methanol. Crude protease produced as described in example 4 was incubated at 28° C. with 20% (v/v) organic solvents (effective concentration). Samples were removed at different time intervals and residual activity was estimated. Sample without organic solvent served as control. Initial activity with respective solvents was taken as 100% (Table 17). The protease was stable in presence of organic solvents with the exception of butanol which showed 75.26% residual activity while more than 95% activity was retained in all other solvents up to 5 h. After 12 h incubation at 28° C., except butanol, protease retained more than 50% activity while the residual activity in butanol was around 40%. (Table 17).
This example illustrates the effect of water miscible as well as water immiscible organic solvents on stability of crude protease at 37° C. Following organic solvents were used: acetone, acetonitrile, 1-butanol, dimethylsulphoxide, isopropanol and methanol. Crude protease produced as described in example 4 was incubated at 37° C., pH 7 with 20% (v/v) organic solvents (effective concentration). Samples were removed at different time intervals and residual activity was estimated. Sample without organic solvent served as control. Initial activity with respective solvents was taken as 100% (Table 18). The protease was stable in presence of organic solvents with the exception of acetonitrile, butanol and isopropanol which showed less than 35% residual activity while more than 50% activity was retained in acetone, methanol and dimethylsulphoxide after 2 h (Table 18).
This example illustrates the non-collagenase nature of the protease from Conidiobolus brefeldianus MTCC 5185 by fluorescence studies using NMITLI-1 and Collagenase-1 substrates. Initially fluorescence experiments were done with crude as well as purified proteases against NMITLI-1 substrate. Fluorescence experiments were carried out in triethanolamine buffer (TEA) pH 8 at room temperature. Typically, the assay contained 2900 of 100 mM TEA buffer pH 8, having NMITLI-1 substrate concentration of 1.8 μM (10 μl of 112 μM stock solution). The reaction was initiated by adding 5 μl of enzyme samples. The excitation wavelength was 340 nm and the emission was scanned from 425-625 nm, at different intervals of time. There was three fold increase in the fluorescence of AEDANS chromophore (+++) indicating proteolytic nature of the enzyme samples.
As crude as well as purified protease samples showed activity against NMITLI-1 substrate, they were also screened for collagenase activity with Collagenase substrate-I. Fluorescence experiments were carried out in triethanolamine buffer (TEA) pH 8 at room temperature. Typically, the assay contained 290 μl of 100 mM TEA buffer pH 8, having substrate (Collagenase substrate-I) concentration of 1.6 μM (5 μl of 80 mM stock solution). The reaction was initiated by adding 5 μl of enzyme samples. The excitation wavelength was 340 nm and the emission was scanned from 425-625 nm, at different intervals of time. There is no increase in the fluorescence of AEDANS chromophore (−) indicating absence of collagenase activity.
These results indicate that the crude as well as purified proteases from Conidiobolus brefeldianus MTCC 5185 were inactive against Collagenase substrate-1 showing non-collagenase nature of the proteases.
This example illustrates the determination of activity of the protease from Conidiobolus brefeldianus MTCC 5185 towards elastin-orcin. The reaction mixture contained an aliquot of suitably diluted protease enzyme and 20 mg elastin-orcin in 50 mM Tris HCl buffer pH 8.0 in a total volume of 3 ml. Heat inactivated enzyme (by boiling for 15 min) was taken as blank. After incubation at 50° C. for 30 min, contents were filtered on Whatman No 1 filter paper and absorbance of the filtrate was measured at 578 nm. One unit of enzyme activity is defined as the amount of enzyme required to cause an increase in absorbance by one unit at 578 nm in one minute. The ammonium sulphate precipitated suspension as described in example 28 having caseinolytic activity of 118.12 IU/ml showed activity of 3.84 U/ml against elastin-orcin.
This example illustrates the determination of azocoll activity of the protease from Conidiobolus brefeldianus MTCC 5185. The reaction mixture contained an aliquot of suitably diluted protease and 10 mg azocoll in 0.05M Tris HCl buffer pH 8.0 in a total volume of 2.5 ml. Heat inactivated enzyme (by boiling for 15 min) was taken as blank. After incubation at 37° C. for 10 min, the reaction was terminated by filtering through Whatman No. 1 filter paper. The absorbance of filtrate was measured at 580 nm. One unit of enzyme activity is defined as the amount of enzyme required to cause an increase in absorbance by one unit at 580 nm per minute. The crude culture filtrate grown as described in example 3 had an azocoll activity of 16-18 U/ml.
This example illustrates the determination of azocasein activity of the protease from Conidiobolus brefeldianus MTCC 5185. The reaction mixture contained an aliquot of suitably diluted protease and 1 mg azocasein in 0.05 M sodium carbonate buffer pH 9.0 in a total volume of 500 μl. Heat inactivated enzyme (by boiling for 15 min) was taken as blank. After incubation at 50° C. for 30 min, the reaction was terminated by addition of 500 μl of 10% TCA. After cooling on ice for 15 min, contents were centrifuged at 8000 rpm for 10 min. To 800 μl of supernatant, 200 μl of 1.8M NaOH was added and absorbance was measured at 420 nm. One unit of enzyme activity is defined as the amount of enzyme required to cause an increase in absorbance by one unit at 420 nm per minute. The crude culture filtrate grown as described in example 3 showed an activity of 40-45 U/ml.
This example illustrates the activity of crude protease from Conidiobolus brefeldianus MTCC 5185 towards N-α-benzoyl-DL-arginine-p-nitroanilide (BAPNA). The assay mixture consisting of 0.16 ml of 3 mM N-α-benzoyl-DL-arginine-p-nitroanilide (BAPNA) in DMSO, 0.5 ml of 50 mM phosphate buffer pH 7.2 and 0.1 ml of appropriately diluted enzyme sample was incubated at 37° C. for 1 h. Reaction was terminated by addition of 0.5 ml of 1M Na2CO3. Absorbance was measured at 420 nm. One unit of activity is defined as the amount of enzyme required to cause an increase in absorbance by one unit at 410 nm in one minute. The crude enzyme as described in example 3 having caseinolytic activity of 20.7 U/ml showed an activity of 1.41 U/ml
This example illustrates the determination of protease activity from Conidiobolus brefeldianus MTCC 5185 with casein, hemoglobin and bovine serum albumin as substrates. The crude culture filtrate grown as described in example 3 was concentrated by ultra-filtration on PM-10 membrane and used for the studies. The reaction mixture contained an aliquot of suitably diluted protease enzyme and 10 mg substrate in 0.1M sodium carbonate buffer pH 9.0 in a total volume of 2 ml. After incubation at 50° C. for 10 min, the reaction was terminated by the addition of 3 ml of 5% trichloroacetic acid (acidified with concentrated hydrochloric acid). The precipitate formed was filtered through Whatman No. 1 filter paper after standing at room temperature for 30 min. The absorbance of trichloroacetic acid soluble fraction was measured at 280 nm. The protease is able to degrade the above substrates to varying degrees (Table 19).
This example illustrates the effect of inhibitors on protease activity of Conidiobolus brefeldianus MTCC 5185. Following inhibitors were studied: phenylmethylsulfonyl fluoride (PMSF), ethylene-diaminetetraacetic acid (EDTA), iodoacetic acid, and dimeth ylsulphoxide (DMSO). The crude culture filtrate grown as described in example 3 was concentrated by ultra-filtration on PM-10 and YM-3 membranes as described in example 27 and used for inhibition studies. Both the protease preparations were pre-incubated in 100 mM Tris-HCl buffer (pH 8.0) with each inhibitor for 1 h and the residual protease activity was measured at 50° C., pH 9.0. Protease without inhibitor served as control. Protease was completely inhibited by 1 mM PMSF indicating it to be a serine protease (Table 20).
This example illustrates the effect of inhibitors on protease activity of Conidiobolus brefeldianus MTCC 5185. Following inhibitors were studied: N-tosyl-L-phenylalanine chloromethyl ketone (TPCK), N-tosyl-L-lysine chloromethyl ketone (TLCK), and Benzamidine. Crude protease was pre-incubated with each inhibitor in 100 mM Tris-HCl buffer (pH 8.0) for 30 min and the residual protease activity was measured 50° C., pH 9.0. Protease without inhibitor served as control. Inhibition by TPCK and TLCK was 9 and 29% respectively while Benzamidine did not inhibit indicating that the protease does not have trypsin like activity (Table 21).
This example illustrates the pH range in which the lipase secreted by the said strain is active. For determination of optimum pH for lipase, the enzyme was assayed at 50° C. and pH ranging from 4 to 9 by titrimetric method. Following buffers were used: acetate (pH 4 and 5), phosphate (pH 6, 7), Tris HCl (pH 8) and carbonate bicarbonate (pH 9). The results are presented in accompanying Table 22 and forming the part of this specification. It is observed that the enzyme is active between pH 4 and 9.
This example illustrates the temperature range in which the lipase secreted by the said strain is active. For determination of optimum temperature, lipase activity was determined by titrimetric method at pH 7 and at temperatures ranging from 30 to 60° C. The results of the experiment have been illustrated in Table 23 accompanying and forming the part of this specification. It is observed that the enzyme is active between 30 to 60° C.
Conidiobolus brefeldianus MTCC 5185
This example illustrates the purification of the Conidiobolus brefeldianus MTCC 5185 protease to homogeneity. The fungus was grown as described in example 4 and the clear supernatant obtained after centrifugation at 10,000 rpm for 10 min was used as the source of enzyme. Fractional ammonium sulphate precipitation of the broth was carried out at 4° C. and dialyzed ammonium sulphate precipitate (50-80% saturation) was loaded on a diethyl aminoethyl cellulose (DEAE-cellulose) column (2.5 cm×25 cm) equilibrated with 50 mM phosphate buffer pH 7.0. The un-adsorbed enzyme was eluted with 50 mM phosphate buffer pH 7.0 at a flow rate of 20 ml/h. Fractions showing protease activity were pooled, concentrated by speed-vacc and loaded on Sephadex-G-100 column (1.2 cm×150 cm) equilibrated with 50 mM phosphate buffer, pH 7. Column was eluted with 50 mM phosphate buffer pH 7.0 at a flow rate of 12 ml/h. Fractions showing protease activity were pooled and stored at −20° C.
This example illustrates the purity and determination of molecular weight of purified protease by sodium dodecylsulphate polyacryalmide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption ionization time-of-flight (MALD-TOF). The molecular mass marker kit for SDS-PAGE from M/s BioRad (Cat No. 161-0305) consisted of carbonic anhydrase (35.88 kDa), soyabean trypsin inhibitor (27.86 kDa), lysozyme (18.81 kDa), bovine serum albumin (87.55 kDa), phosphorylase b (101.47 kDa) and ovalbumin (52.74 kDa). The molecular mass of the enzyme by SDS-PAGE was found to be around 29 kDa which was slightly lower than the molecular weight of carbonic anhydrase (
The molecular mass of purified protease was also determined by using MALDI-TOF mass spectrometry using a Voyager DE-STR (Applied Biosystems) equipped with a 37-nm nitrogen laser. The purified enzyme was mixed with equal volume of sinapinic acid in acetonitrile and 20 μl of prepared sample was placed on MALDI plate for analysis. The purified enzyme showed the molecular weight of 27.8 kDa in MALDI-TOF (
Crude protease produced as described in example 6 was spray dried with 10% and 15% maltodextrin as additives with inlet temperatures of 150-160° C. and outlet temperatures of 60-65° C. and 70-80° C. respectively with 70-80% recoveries. The stability of spray dried protease was studied at temperatures ranging from 4° C. to 37° C. Samples were distributed in vials and stored at 4° C., 28° C. and 37° C. One vial incubated at each temperature was removed at regular intervals and residual activity was checked. Spray dried protease was stable up to 25 months (760 days) at all the temperatures tested and retained 85-90% activity (
This example illustrates the removal of silver from waste X-ray film using crude protease, biomass filtrate and biomass of Conidiobolus brefeldianus MTCC 5185.5 g black X-ray film cut in to 1 cm×1 cm pieces were washed with distilled water. These pieces were incubated with 20 U of protease in 10 mM carbonate bicarbonate buffer, pH 9 in a total volume of 50 ml in 250 ml conical flask at 37° C. and 180 rpm. A control without protease was also incubated under identical conditions. Stripping of gelatin layer from the film started within few minutes and was complete within 1 h. The solution looked blackish due to the blackish silver and the film was clean and white (
This example illustrates the use of protease from Conidiobolus brefeldianus MTCC 5185 for degumming of silk. Silk twists were dried in oven at 110° C. for 3 h (or till constant weight reached). 1 g dried silk was incubated with crude protease prepared as described in example 3 at 50° C. with intermittent manual shaking for 1 h. Four different protease concentrations (50 to 200 U/g of silk) were used for degumming. Solid to liquid ratio was kept at 1:30. After degumming, silk fiber was washed first with tap water (cold wash) followed by a hot wash (65° C. for 20 min). After washing, silk was air dried overnight before drying in oven (110-120° C.) for 2 to 3 h (or till constant weight reached) and weight of the degummed silk was recorded. Loss in weight after degumming was calculated from the difference in initial and final weights. Loss in weight after degumming increased with increase in enzyme concentration and ranged from 13 to 22% (Table 24). The weight loss for conventionally degummed fiber was around 24.4%. The fiber obtained had smooth feel and luster (
This example illustrates the use of protease from Conidiobolus brefeldianus MTCC 5185 for degumming of silk and separation of serecin proteins/peptides from degumming liquor. 4 g silk twists was dried in oven for 3 h at 110° C. (or till constant weight reached) and incubated with 800 U of protease prepared as described in example 3 at 50° C. with intermittent manual shaking for 1 h. Solid to liquid ratio was kept at 1:30. After degumming, silk fiber was washed first with tap water (cold wash) followed by a hot wash (65° C. for 20 min). After washing, silk was air dried overnight before drying in oven (110-120° C.) for 2 to 3 h (or till constant weight reached) and weight of the degummed silk was recorded. Loss in weight after degumming was around 20%. The insoluble sericin (whitish residue) from degumming liquor (DGL) was separated by centrifugation at 6000 rpm for 5 min. This insoluble residue was suspended in double distilled water and was subjected to sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Serecin obtained by conventional method (autoclaving at 121 for 60 min) was included for comparison. Three protein bands were visualized after silver staining incase of enzymatic degumming whereas there was a streak on the gel for serecin obtained by conventional method, indicating its complete degradation (
This example illustrates the process for unhairing of goat skins by paste method using crude protease from Conidiobolus brefeldianus MTCC 5185. The protease produced as described in example 6 was subjected to ammonium sulphate precipitation (90% saturation) and used for dehairing studies. Wet salted goat skins were taken and soaked for 6 hours. After soaking the weight of the skin was noted. A paste of 0.5 to 1.5% protease and 10% water based on the soaked weight was applied on the flesh side of the skin and piled for 6 hours. A corresponding chemical based control process was also carried out using paste of 10% lime, 3% sulfide and 15% water. The control skins were also piled for 6 hours. Then both control and experimental skins were unhaired and the unhairing efficacy of experimental skins ranged from 85 to 100% which was found to be similar to the unhairing efficacy in chemical based unhairing process. The pelts were clean and free from scud. The dehaired pelts were tanned and further processed into crust leathers and the quality of the crust leathers was also assessed. The quality of leather in terms of tensile strength, tear strength and grain bursting strength were comparable to that obtained by lime and sulphide based dehairing. The reduction in pollution load was also assessed by analyzing the waste streams of both control and experimental process. The results indicate that there was significant reduction in COD and sulfide. The BOD/COD ratio of the waste stream of experimental process was found to be 0.72 which indicates that the degradability and treatability of the wastewater is much better compared to the wastewater of chemical process system, the BOD/COD ratio of which was 0.4.
This example illustrates the process for unhairing of cow hides using crude protease from Conidiobolus brefeldianus MTCC 5185. The protease produced as described in example 6 was subjected to ammonium sulphate precipitation (90% saturation) and used for dehairing studies. Wet salted cow hides were washed and soaked for 8 hours. After soaking, the weight of the hides was noted. The hides were treated in drums using 15% water and 3-4% enzyme. A corresponding chemical based control process was also carried out using 150% water, 10% lime and 3% sodium sulfide. In the case experimental process, the drum was run intermittently for 10 minutes for every hour. After six hours of running, the pelts were washed. The unhairing was 100%. In the case of control, the drum was run for a day intermittently for 5 minutes for every hour. Next day the pelts were unhaired and the unhairing efficacy was 100%. The experimental pelts were clean and free from scud. The dehaired pelts were tanned and further processed into crust leathers and the quality of the crust leathers was also assessed. The quality of leather in terms of tensile strength, tear strength and grain bursting strength were comparable to that obtained by lime and sulphide method of dehairing. The reduction in pollution load was also assessed by analyzing the waste streams of both control and experimental process. The results indicate significant reduction in COD and sulfide with BOD/COD ratio of 0.69 in the case of experiment, which indicates that the degradability and treatability of the wastewater are enhanced.
This example illustrates the process for unhairing of sheep skins by paste method using crude protease from Conidiobolus brefeldianus MTCC 5185. The protease was produced as described in example 6. This was subjected to ammonium sulphate precipitation (90% saturation) and used for dehairing studies of sheep skins. Wet salted sheep skins were washed and soaked for 5 hours. After soaking the weight of the skin was noted. A paste of 0.5 to 1.5% protease and 10% to 15% of water based on the soaked weight was prepared and applied on the flesh side of the skin. The skins were piled for 6 hours. A control process based on chemicals was also carried out using paste of 10% lime, 3% sulfide and 15% water. The control skins were also piled for 6 hours. Then both control and experimental skins were unhaired and the unhairing efficacy of experimental skins ranged from 85 to 100% which was found to be similar to the unhairing efficacy in chemical based unhairing process. The pelts were clean and free from scud. The dehaired pelts were tanned and further processed into crust leathers and the quality of the crust leathers was also assessed. The quality of leather in terms of tensile strength, tear strength and grain bursting strength were comparable to that obtained by lime and sulphide based dehairing. The reduction in pollution load was also assessed by analyzing the waste streams of both control and experimental process. The results indicate that there was significant reduction in COD and sulfide. The BOD/COD ratio of the waste stream of experiment was found to be 0.70. This indicates that the degradability and treatability of the wastewater from experiment is improved.
This example illustrates the process for unhairing of buffalo hides using crude protease from Conidiobolus brefeldianus MTCC 5185. The protease produced as described in example 6B was subjected to ammonium sulphate precipitation (90% saturation) and used for dehairing studies. Wet salted buffalo hides were taken, washed and soaked for 8 hours. After soaking, the weight of the hides was noted. The hides were treated in drums using 15% water and 3-4% enzyme. A corresponding chemical based control process was also carried out using 150% water, 10% lime and 3% sodium sulfide. In the case experiment, the drum was run intermittently for 10 minutes for every hour. After six hours of running, the pelts were washed. The unhairing was 100%. In the case of control the drum was run for a day intermittently for 5 minutes for every hour. Next day the pelts were unhaired and the unhairing efficacy was 100%. The experimental pelts were clean and free from scud. The dehaired pelts were tanned and further processed into crust leathers and the quality of the crust leathers was also assessed. The quality of leather in terms of tensile strength, tear strength and grain bursting strength were comparable to that obtained by lime and sulphide method of dehairing. The reduction in pollution load was also assessed by analyzing the waste streams of both control and experimental process. The results indicate significant reduction in COD and sulfide with BOD/COD ratio of 0.74 in the case of experiment, which indicates that the degradability and treatability of the wastewater are enhanced.
This example describes the application of protease in detergent formulation. A piece of white cloth was dipped in blood and air dried. The blood stained cloth was cut into four equal parts of 0.5 g each and dipped in 2% formaldehyde for 2 min in 4 different petri plates and rinsed with water to remove excess formaldehyde. The pieces were dipped in 30 ml of reaction mixture and incubated at 28-30° C. for 30 min under different conditions: (a) control (only water) (b) Only detergent (c) Only crude protease (10 U) and (d) detergent+crude protease (10 U). The cloth pieces were rinsed 4 times with tap water. The washing performance was best where detergent and protease was used together. Blood clots were not removed with only detergent while protease alone was able to remove blood stain along with clots (
The main advantages of the present invention are the following
| Number | Date | Country | Kind |
|---|---|---|---|
| 437/DEL/2010 | Feb 2010 | IN | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IB11/00516 | 3/11/2011 | WO | 00 | 1/11/2013 |
