30 results about "Cutinase" patented technology

The invention discloses keratinase Phyto-Keratinase and application of the keratinase Phyto-Keratinase. The keratinase Phyto-Keratinase comprises the following components: (1) protease which is coded by a nucleotide sequence as shown in SEQ ID NO.1; and / or (2) protease which is derived from bacillus subtilis, is coded by a nucleic acid sequence with more than 98% of identity with the SEQ ID NO.1 nucleotide sequence and has the characteristic of hydrolyzing keratin. According to the plant keratinase Phyto-Keratinase disclosed by the invention, the Phyto-Keratinase (plant keratinase) produced by utilizing microbial fermentation is a serine proteolytic enzyme, is also a biocompatible cutinase, and is obtained by fermenting saccharomyces cerevisiae. Phyto-Keratinase provides a nitrogen source for the growth of plants (beans), and contains various amino acids (functional peptides) and special proteolytic enzymes derived from the plants at the same time. The Phyto-keratinase can provide the effects of resisting inflammation, removing cutin and providing nutrition for skin regeneration at the same time, can relieve various inflammations by inhibiting PAR-2 receptors, and has potential value in the fields of cosmetics, beauty medicine and environment.

The invention discloses low-temperature cutinase CtCut derived from marine fungi and capable of efficiently degrading PU and PET plastics and application of the low-temperature cutinase CtCut. The amino acid sequence of the low-temperature cutinase CtCut is shown as SEQ ID NO. 2, and the nucleotide sequence of the low-temperature cutinase CtCut is shown as SEQ ID NO. 1. The CtCut can degrade various polyurethanes (PU) such as polyester type PU ImpranilTMDLN, polyether type PU foam and PBA-PU at the temperature of 35 DEG C, and also has a degradation effect on polyethylene glycol terephthalate (PET). The CtCut can efficiently break ester bonds in PET, ester bonds in a PU soft segment and carbamate bonds in a PU hard segment. The cutinase CtCut has substrate heterogeneity, can efficiently degrade PET (Polyethylene Terephthalate) and PU (Polyurethane) plastics, and can provide theoretical guidance and technical support for recycling various types of PU and mixed plastics in the future.

The invention belongs to the technical field of polyester surface modification, and relates to a method for promoting cutinase to hydrolyze polyester by using triton. The method comprises the following steps: adding triton into a Tris-HCl buffer solution, uniformly mixing, and adjusting the pH value with hydrochloric acid to obtain a triton buffer solution; and immersing the refined terylene into a triton buffer solution, adding a cutinase preparation for hydrolysis reaction, inactivating cutinase, taking out the terylene, washing and drying. Triton is used as an additive to improve the activity and stability of cutinase, promote the hydrolysis effect of cutinase on polyester, and increase the hydrolysis release product by 229.8%, so that cutinase can hydrolyze polyester with higher crystallinity.

The invention relates to cutinase as well as a coding gene and application thereof. The amino acid sequence of the cutinase SCC is as shown in SEQ ID NO. 1, and the nucleotide sequence of the cutinase SCC is as shown in SEQ ID NO. 2. The inventor of the application finds out a novel cutinase SCC of a serine hydrolase family from Saccharothrix carnea, and the cutinase SCC is easy for heterologous expression and purification, and can efficiently and specifically catalyze and degrade mono (2-hydroxyethyl) terephthalate (MHET) and polyethylene glycol terephthalate (PET). And compared with the existing MHET degrading enzyme, the MHET degrading enzyme has the advantages that the catalytic efficiency is obviously improved, the use amount of the enzyme can be effectively reduced in the process of catalytically degrading MHET and PET, and the use cost of the enzyme is reduced.

The application discloses a controllable preparation method of high-activity earthworm protein peptide and belongs to the technical field of earthworm processing. The preparation method comprises the following steps: (1) adding amylase and cutinase to earthworm paste for hydrolysis; (2) filtering by using a filter; (3) hydrolyzing the filtrate by using a composite enzyme; (4) adding alkaline protease to the filter residue for hydrolysis, and then adding high-temperature protease for hydrolysis; (5) filtering the hydrolyzed paste, and then filtering and treating the paste by using a ceramic microfilter to obtain low-molecular-weight earthworm protein peptide; and (6) mixing the obtained earthworm water-soluble protein hydrolysate and the obtained earthworm insoluble protein polypeptide, and then concentrating and drying to obtain high-activity earthworm protein peptide. According to the application, the water-soluble protein and the water-insoluble protein in the earthworm are step-by-step differentially hydrolyzed, the protein resources in the earthworm are maximally utilized, the polypeptide / protein yield can be more than 85%, waste is avoided, and the activity of the obtained protein peptide is ensured.

The invention discloses a leaf and branch compost cutinase link and application thereof, and belongs to the technical field of enzyme molecule construction. The leaf-branch compost cutinase kink is obtained by adjusting the connection sequence of fragments in leaf-branch compost cutinase, and comprises a fragment II, a connecting peptide fragment I, a fragment I, a connecting peptide fragment II and a fragment III which are connected in sequence from the N end to the C end; wherein the fragment I, the fragment II and the fragment III respectively correspond to 37th to 79th amino acids, 81st to 143rd amino acids and 150th to 293rd amino acids or homologous sequences thereof of the leaf branch compost cutinase. According to the method, protein topology engineering and an artificial intelligence assisted protein design technology are organically combined, knot topology transformation is performed on the leaf branch compost cutinase, sequence optimization is performed on a connecting peptide fragment of the knot, and the leaf branch compost cutinase knot with good biological activity is obtained; the expression quantity and the stability of the leaf and branch compost cutinase kink are improved, the problem of kinetic barriers existing in protein kink combination is solved, and the method has important application value.

The invention belongs to the technical field of degradation of waste textiles, and relates to a method for improving enzymolysis efficiency of polyester through pretreatment of an alkaline eutectic solvent, which comprises the following steps: mixing a hydrogen bond donor and a hydrogen bond acceptor, heating and stirring until the mixture is clear and transparent to obtain the eutectic solvent; the preparation method comprises the following steps: soaking terylene in a deep eutectic solvent, separating out terylene, and washing with ethanol and deionized water until the pH is neutral, so as to obtain pretreated terylene; cutinase is dissolved in a Tris-HCl buffer solution to obtain an enzymolysis solution, pretreated polyester is immersed for a reaction, and then inactivation is performed. The deep-eutectic solvent is adopted for promoting cutinase to conduct enzymolysis on the polyester, the deep-eutectic solvent has the advantages of being simple in preparation method, low in cost, biodegradable, recyclable and non-toxic, the crystallization degree of the polyester is reduced through the CHCl / EA deep-eutectic solvent, then enzymolysis is conducted, and the total product release amount of enzyme hydrolysis is increased by 5 times.

The invention relates to the technical field of enzyme engineering and recombinant protein expression, and discloses a mutant for improving cutinase yield and a preparation method thereof. The mutant protein is based on an amino acid sequence as shown in SEQ ID NO.1 and has G93Q or H209F single-point substitution, and the site number takes first methionine in the SEQ ID NO.1 as the first site. The invention also provides a nucleic acid molecule for coding the mutant, a recombinant expression vector and a recombinant host cell, and a method for adding an inducer to induce expression when OD600 is 0.6-1.2 in a culture process so as to obtain a culture containing the mutant. Embodiments show that the enzyme activity per unit volume of the mutant culture is higher than that of a control group.

The present invention relates to a method for treating a textile comprising a polyester with low crystallinity by contacting the textile with a cutinase, as well as a textile produced by such method.

The application discloses a cutinase mutant and application thereof to efficient degradation of PET. The amino acid sequence of the cutinase mutant is shown in SEQ ID NO. 2, and is obtained by replacing phenylalanine at the 239th amino acid in the amino acid sequence of a wild-type cutinase shown in SEQ ID NO. 1 with alanine. The cutinase mutant is expressed in E. coli, and compared with the wild-type enzyme, the activity of the mutant enzyme is increased in stability, the catalytic efficiency is improved, and the yield of a PET plastic (polyethylene terephthalate, PET) degradation product is increased by 42.6 times. The improved cutinase mutant improves the PET degradation efficiency, reduces the production cost, and is more suitable for industrial application.

This invention discloses a BhrPETase keratinase mutant and its application in the degradation of polyethylene terephthalate (PET), belonging to the fields of environmental science and enzyme engineering. The site numbers are based on the amino acid sequence shown in SEQ ID NO:1. The mutant contains substitutions of S14G, H78Y, and S184G relative to SEQ ID NO:1, with the preferred amino acid sequence shown in SEQ ID NO:9. Under conditions of 1 mg enzyme protein / g substrate, 65°C, and 96 h, the preferred mutant exhibits a degradation rate of 90.4% for PET membranes and a half-life of 150 h at 60°C, making it suitable for enzymatic degradation and depolymerization of PET.

The invention discloses a cutinase mutant and application thereof in degradation of polyethylene glycol terephthalate, and belongs to the field of environmental science. According to the present invention, BhrPETase derived from bacteria HR29 and LC cutinase of a metagenome in plant compost are modified to obtain mutants, the mutants are subjected to single-point or multi-point mutation near the substrate binding site of the BhrPETase or the LC cutinase, and the 184th site and the 156th site are subjected to single-point mutation or combined mutation to construct six mutants; compared with a wild type enzyme, the six mutants (M1-M6) have the advantages that the enzyme activity and the PET degradation efficiency are obviously improved, and the industrial prospect is good.

The application discloses a wool tricarboxylic acid blended fabric and a preparation method thereof, and belongs to the technical field of textile printing and dyeing. The method comprises the following steps: respectively performing normal-pressure low-temperature plasma pretreatment and specific enzyme synergistic modification on wool sliver and tricarboxylic acid short fiber sliver, moderately passivating wool scales by using protease, and promoting surface micro-deacetylation of tricarboxylic acid by using esterase or cutinase; mixing the slivers, spinning and weaving into a fabric; performing one-bath same-color dyeing by using disperse / acid dyes at 100 DEG C under normal pressure; and performing medium-low temperature heat setting. Through synergistic effect of plasma physical etching and biological enzyme chemical degradation, the technical prejudice that tricarboxylic acid needs high-temperature dyeing at 130 DEG C is broken. The method can obtain excellent same color under normal pressure, significantly improves wool strength retention rate, avoids wool heat damage and yellowing, the finished product has low shrinkage rate after machine washing, is green and environment-friendly, and is suitable for industrial popularization.

The invention discloses a coding gene of cutinase CutBJB6 for synthesizing a plurality of fatty acid ethyl esters from a Lacnella arida source and an application of the coding gene of cutinase CutBJB6. The amino acid sequence of the cutinase CutBJB6 is as shown in SEQ ID NO. 1, and the nucleotide sequence of the coding gene of the cutinase CutBJB6 is as shown in SEQ ID NO. 2. The invention belongs to the technical field of biosynthesis, and particularly discloses a coding gene of the Lacnellada-derived cutinase CutBJB6 and construction of an escherichia coli expression vector carrying the gene, and also discloses application of the Lacnellada-derived cutinase CutBJB6 in catalytic synthesis of ethyl butyrate, ethyl valerate, ethyl hexanoate, ethyl caprylate and ethyl caprate in a water-phase system. The invention further discloses a preparation method of the Lacnellada-derived cutinase CutBJB6 and application of the Lacnellada-derived cutinase CutBJB6 in the field of biosynthesis of the Lacnellada-derived cutinase CutBJB6. The invention firstly provides the cutinase CutBJB6 which has the capability of synthesizing fatty acid ethyl ester in a water phase system and is derived from the Lacnella arida and the coding gene of the cutinase CutBJB6.

The application discloses a cutinase capable of degrading polyester plastic and application thereof. The application provides a cutinase gene capable of degrading polyester plastic, wherein the nucleotide sequence of the cutinase gene is SEQ ID NO. 1, and the amino acid sequence of the coded cutinase protein is SEQ ID NO. 2. The cutinase can destroy the complete structure of plastic, and the surface of the plastic appears holes, cracks and other erosion. In addition, the cutinase can degrade different types of polyester plastic, wherein the weight loss rates of PUR foam and polyester plastic PCL reach 33.88% and 83.44% respectively within 2 days, and the degradation rates of agricultural degradable mulch PBAT and PU plastic synthetic oligomer PBA-PU reach 66.70% and 64.41% respectively within 4 days. The cutinase gene can be widely applied to degradation and resource utilization of waste polyester plastic as an element.

The invention discloses cutinase ChCut1 with a function of degrading polyurethane plastics. The amino acid sequence of the cutinase is shown as SEQ ID NO. 1. The invention also provides an extracellular expression method and application of the cutinase. The cutinase can be massively expressed in the saccharomyces cerevisiae, so that the efficient, stable and low-cost cutinase is produced. The cutinase can effectively degrade Impranil PU (polyurethane) under the condition of 28 DEG C, so that a plastic polymer structure is destroyed, and biodegradation under a mild condition is realized.

The application discloses a marine-derived cutinase mutant and a preparation method and application thereof. Compared with a wild-type strain, the mutant of the marine-derived cutinase NSHC has an optimal temperature increased by 10 DEG C, an enzyme activity increased by 3.7 times, and the amount of a final product in the process of degrading PBAT is increased by 3.35 times. The mutant of the marine-derived cutinase NSHC enriches the types of marine-derived cutinases, can effectively degrade PBAT, improves plastic pollution in the environment, and has a wide application prospect.

The application discloses a salt-tolerant cutinase mutant of hydrolyzed polyethylene terephthalate and application thereof. Streptomyces alkaliphilus PET cutinase Sa Cut27 is obtained through mutation, and the amino acid sequences are shown in SEQ ID NO. 3-15 in sequence. PET cutinase Sa Cut27 can exhibit PET degradation activity in a high-salt environment, and 4.17 mM of degradation products can be obtained under the action of 2 M NaCl at 50 DEG C for 48 h, which is better than Is PETase. Compared with the original PET degradation enzyme, the heat stability and / or specific activity of the obtained mutant are significantly improved. The enzyme has wide application prospects in the fields of marine plastic recycling, high-salt wastewater treatment and high-ion-strength reaction systems.

The application discloses a kind of extracellular secretion mussel protein genetically engineered bacteria and its construction method and application, belong to genetic engineering technical field.The application is connected by signal peptide screening, and signal peptide is connected with the gene of mussel protein and is transferred into plasmid pET-Duet and is fused expression.Further, the application is transferred into plasmid pET-Duet with cutinase Tfu-0883 gene, and signal peptide-mussel protein fusion protein is co-expressed, and finally realizes the extracellular secretion of mussel protein.In addition, the application optimizes fermentation medium by adding surfactant, thereby improving extracellular secretion level.The yield of mussel protein in purified fermentation broth can reach 20-40mg / L.The application realizes the extracellular secretion of soluble mussel protein with biological activity in escherichia coli, weakens the cytotoxicity caused by product accumulation, promotes the sustained synthesis of mussel protein, and avoids subsequent cell disruption operation, and optimizes the process.

The invention provides a screening method of plastic degrading bacteria, and belongs to the technical field of microorganisms. The screening method provided by the invention comprises the following steps: separating and screening candidate plastic degrading bacteria with plastic degrading capability from intestinal tissues of greater wax moth's larva which is fed with a PE (Poly Ethylene) film; co-culturing the candidate plastic degrading bacteria and the PE film, and when the PE film is perforated, secreting plastic degrading related enzymes, namely the plastic degrading bacteria; the plastic degradation related enzyme is one or more of laccase, peroxidase and cutinase; the plastic degrading bacteria are one or two of bacillus subtilis and bacillus cereus. The screening method disclosed by the invention can be used for successfully screening strains with plastic degradation capability, and a new strain can be provided for plastic degradation by researching the degradation characteristics of the obtained strains.

The invention discloses a leaf and branch compost cutinase Soxhlet and a preparation method thereof, and belongs to the technical field of enzyme molecule construction. The leaf branch compost cutinase Soxhlet comprises a first unit ring and a second unit ring which are interlocked, the first unit ring comprises a first fragment, a first connecting peptide fragment, a third fragment and a second connecting peptide fragment which are sequentially connected to form a ring, and the second unit ring comprises a second fragment and a third connecting peptide fragment which are sequentially connected to form a ring; the fragment I, the fragment II and the fragment III respectively correspond to 36th to 64th amino acids, 72th to 151st amino acids and 159th to 293th amino acids or homologous sequences of the 36th to 64th amino acids, the 72th to 151st amino acids and the 159th to 293th amino acids of the linear leaf and branch compost cutinase amino acid sequence. The Soxhdrocarbon design is constructed by splitting a linear leaf branch compost cutinase structure and introducing an artificially designed connecting peptide fragment, the sequence of the connecting peptide fragment is optimized by an artificial intelligence assisted protein design method, and based on an orthogonal cyclization element mediated coupling reaction, the leaf branch compost cutinase Soxhdrocarbon with good biological activity is obtained.

The invention discloses a high-activity immobilized plastic degrading enzyme preparation and application thereof, and belongs to the technical field of plastic degradation. The enzyme preparation is prepared by the following steps: by taking pinus tabulaeformis pollen as a raw material, performing acid treatment, carbonization and activation to form a hierarchical porous active pollen carrier; through lanthanum-doped magnetic nanoparticle modification and sulfydryl functional modification, the carrier is endowed with magnetic responsiveness and directional fixed sites; a three-dimensional cross-linked structure is constructed by using a triazine ring rigid conjugated monomer and a hyperbranched network, and spatial confinement immobilization of enzyme molecules is realized by combining an ultraviolet click reaction; and cutinase, lipase, cellulase, laccase and peroxidase are synergistically loaded to form a multi-enzyme catalytic system. By combining pollen-based hierarchical pore channels with a triazine ring rigid network, the enzyme loading capacity and distribution uniformity are remarkably improved, the enzyme activity retention rate of 90% or above is still kept after an enzyme preparation is recycled for 10 times through cross-linked network protection, and rapid magnetic separation is achieved through lanthanum-doped ferroferric oxide nanoparticles.

The application discloses a method for improving catalytic degradation of PET plastic by cutinase, and the method comprises the following steps: preparing a high-molecular condensed phase, collecting a concentrated phase of the condensed phase by centrifugation, adding LCC-ICCG-218Y enzyme solution and PET solid to the concentrated phase, and oscillating to make the concentrated phase uniformly distributed in the reaction system, starting the reaction under oil bath at 40-72 DEG C, collecting the reaction liquid, and characterizing the degradation product of the reaction liquid by ultraviolet. Compared with a phosphate buffer solution, the degradation rate of PET plastic at 40 DEG C and 50 DEG C is finally doubled. The method establishes a simple method for improving enzymatic hydrolysis of PET plastic, and only by adjusting the reaction microenvironment of the enzyme, without complex protein modification and enzyme immobilization means, the method has certain application value.

The invention discloses a cutinase mutant with remarkably enhanced catalytic efficiency on polyvinyl acetate and application of the cutinase mutant, and belongs to the technical field of enzyme engineering and genetic engineering. The combined mutant C11 provided by the invention shows that the catalytic efficiency on polyvinyl acetate is obviously improved, and the yield of a degradation product acetic acid is 1.73 times that of M8. In addition, the half-life period of C11 at 70 DEG C is 205.9 hours, and the half-life period is prolonged by 5.17 times compared with the half-life period of M8. Meanwhile, the stability of the C11 in an alkaline environment is enhanced, so that the C11 has higher alkali resistance, and the application potential of the C11 under an alkaline condition is widened. The cutinase mutant provided by the invention represents a biocatalyst which has a great prospect in application of industrial paper pulp and paper.

The invention relates to the technical field of diglyceride preparation, in particular to a preparation method of diglyceride with a uric acid reducing effect. Comprising the following steps: (1) vegetable oil is partially hydrolyzed with a complex enzyme composed of lipase and cutinase, a hydrolysate is obtained after dehydration, and the content of free fatty acid in the hydrolysate is 37.0 wt%-46.0 wt%; and (2) adding glycerol and lipase into the hydrolysate obtained in the step (1) to react, adding water to remove excessive glycerol, standing for layering, collecting supernatant, and carrying out distillation separation to obtain the edible diglyceride. The content of diglyceride in the final product reaches 80% or above by strictly controlling enzyme composition and free fatty acid in the hydrolysis and esterification processes, the reaction process is carried out according to the hydrolysis and esterification sequence, the process steps are simple, no organic solvent is used in the whole reaction process, green and environment-friendly effects are achieved, and the obtained diglyceride has a remarkable uric acid reducing effect.

The invention belongs to the technical field of pesticide synthesis, and particularly relates to a preparation method of a novel bactericide pydiflumetofen, which comprises the following five steps: firstly, catalyzing 1-(2, 4, 6-trichlorophenyl)-propyl-2-ketone and hydroxylamine to oximate by adopting cutinase in a phosphate buffer solution; after oximation reaction, inserting a nickel / copper electrode, and carrying out electrochemical methylation by taking dimethyl carbonate as a methylation reagent; adding ethanol and a Pd (OH) 2 / C catalyst into the methylation product, and completing photocatalytic reduction under visible light to obtain O-methyl N-[1-methyl-2-(2, 4, 6-trichlorophenyl)-ethyl]-hydroxylamine; the method comprises the following steps: firstly, carrying out a substitution reaction on O-methyl N-[1-methyl-2-(2, 4, 6-trichlorophenyl)-ethyl]-hydroxylamine and 3-difluoromethyl-1-methyl-1H-pyrazole-4-formyl chloride, and then, carrying out a substitution reaction on O-methyl N-[1-methyl-2-(2, 4, 6-trichlorophenyl)-ethyl]-hydroxylamine and 3-difluoromethyl-1-methyl-1H-pyrazole-4-formyl chloride, so as to

Enzymes are disclosed that have anti-pilling properties and may be used in washing or cleaning agents. A washing or cleaning agent, in particular a liquid detergent, may include a cutinase. A method for cleaning textiles using such a washing or cleaning agent may be useful for removal of soiling, for reducing the pilling effects on textiles, for improving the anti-greying effects, for improving the cleaning performance of such a washing or cleaning agent, and combinations thereof. The cutinase may have at least 65% sequence identity with the amino acid sequence set forth in SEQ ID NO:1 over the entire length thereof and have at least one or more amino acid substitutions at positions 61, 63, 66, 89, 90, 92, 155, 177, 208 and 211.

The invention discloses recombinant escherichia coli with high yield of cutinase and a fermentation amplification process thereof, and relates to the technical field of enzyme engineering, and the fermentation amplification process comprises the following steps: firstly, constructing a fusion tag, a signal peptide, a cutinase coding gene and a promoter on a pET-32a (+) vector, transforming into E.coli JM109 competent cells, culturing, extracting, digesting, sequencing and verifying to obtain recombinant plasmids; then transferring the plasmid into E.coli BL21 (DE3), and carrying out IPTG (isopropyl-beta-d-thiogalactoside) induction to obtain recombinant escherichia coli with high yield of cutinase; the method comprises the following steps: inoculating an activated strain of recombinant Escherichia coli with high yield of cutinase into a fermentation tank after secondary propagation, culturing for 5 hours, supplementing materials in a gradient manner after dissolved oxygen rebounds to maintain the exponential growth of thalli, cooling to 30 DEG C when the OD600 of a fermentation liquid is close to 50, and feeding lactose at a constant flow rate for induction to finish fermentation.

The invention belongs to the technical field of treatment of textiles or analogues, and particularly relates to the technical field of washing of fiber products, in particular to a preparation method of a machine washable cashmere sweater. The method comprises the following steps: cleaning cashmere fibers containing skin to obtain cleaned fibers; the bath ratio for cleaning is 1: (20-50); the use amount of a detergent used for cleaning is 1-2.5% (o.w.f); the cleaning comprises ultrasonic cleaning, and the frequency of the ultrasonic cleaning is 17-50 kHz; the power of ultrasonic washing is 0.3-0.5 W / cm < 3 >; the cleaning time is 2 to 15 minutes; performing enzyme treatment on the cleaned fibers by using a compound enzyme solution to obtain enzyme treated fibers; the compound enzyme solution comprises cutinase, and the using amount of the cutinase is 4-10 mL / g; the enzyme treatment time is 5-6 hours; adjusting the pH value of the compound enzyme solution to 8-8.5 by using a buffer solution; the fiber bath ratio after cleaning is 1: (20-50). According to the method, heavy non-protein components of the skin are directionally decomposed through specific low-frequency ultrasonic waves in cooperation with single-component cutinase, the skin removal rate is increased, and then the machine washable capacity of the cashmere sweater is improved through a series of treatment methods.

The invention discloses a cutinase mutant gene, a protein expressed by the cutinase mutant gene and application of the cutinase mutant gene. The protein expressed by the cutinase mutant gene can be correctly folded and can be massively purified in an escherichia coli system. Meanwhile, the mutant protein disclosed by the invention has the function of degrading PET (Polyethylene Terephthalate) by wild cutinase, and the catalytic efficiency of the protein expressed by the cutinase mutant gene is improved compared with that of a control group. The protein expressed by the keratin mutant gene has activity and stability at 40-80 DEG C. Specifically, when the pH value is 8.0 and the temperature is 72 DEG C, the PET degradation capacity is improved by 20% compared with that of a control group, and when the pH value is 8.0 and the temperature is 60 DEG C, the PET degradation capacity is improved by 70% compared with that of the control group.