252 results about "Whole cell" patented technology

The invention discloses a biosynthesis system for high-yield 1, 6-hexamethylenediamine and application of the biosynthesis system, and belongs to the technical field of biology. According to the method, key genes which are excavated and optimized in a 1, 6-hexamethylenediamine biosynthetic pathway are co-expressed in a single cell module or a multi-cell module, and different enzyme elements expressed by the cell module are subjected to enzyme cascade reaction, so that 1, 6-hexamethylenediamine can be efficiently synthesized by taking caprolactam or 6-aminocaproic acid as a substrate; furthermore, after the carboxylic acid reductase MaCAR is mutated, the catalytic activity of the carboxylic acid reductase MaCAR can be remarkably improved, and the yield of the 1, 6-hexamethylenediamine is further improved; in addition, the biosynthesis system disclosed by the invention directly takes the cell module as a whole-cell catalyst, and an enzyme purification step is avoided, so that the biosynthesis system has the advantage of low cost.

The invention discloses an arginine decarboxylase diaA enzyme mutant and application thereof in preparation of butanediamine, and belongs to the field of bioengineering. According to the invention, rational charge overturning transformation is simultaneously carried out on a pentamer meridian oligomeric interface and a dimer latitudinal oligomeric interface, so that stable assembly and efficient catalysis of the decamer under the condition of neutral to alkaline pH (7.0-9.0) are realized. Wherein positive charges are introduced into a meridian interface to weaken electrostatic repulsion, and negative charges are introduced into a latitudinal interface to enhance dimer compactness and substrate transfer efficiency. The specific enzyme activity of the representative double mutant AdiAD110K / H736E at pH 8.0 is about 35 times that of a wild type, and the representative double mutant AdiAD110K / H736E keeps a complete decamer state in a pH range of 7.0-9.0. The yield of butanediamine is up to 145.9 g / L under the whole-cell catalysis of the mutant.

The invention relates to a photovoltaic module, the photovoltaic module comprises three battery string groups which are connected in series, each battery string group comprises four battery strings which are connected in parallel, each battery string comprises a plurality of fragmented battery pieces, and each fragmented battery piece is a quarter piece formed by cutting a whole battery piece; the three battery string groups which are connected in series are distributed along a first direction, and a plurality of fragmented battery pieces in the battery strings are distributed along a second direction; the heads and the tails of the battery strings are connected with the bus bars, the bus bars comprise first bus bars located at the two ends of the photovoltaic module in the second direction and second bus bars located in the middle of the photovoltaic module in the second direction, and the first bus bars are located on the back face of the photovoltaic module. According to the photovoltaic module, on one hand, one half of the fragmented battery piece in the battery string is replaced by one fourth of the fragmented battery piece, and on the other hand, the photoelectric conversion efficiency of the photovoltaic module is relatively high by enabling the first bus bar to be located on the back surface of the photovoltaic module.

Provided are S-adenosylmethionine synthetase mutants and the use thereof, belonging to the technical field of biological enzyme engineering. Site-directed combinatorial mutations are performed on positions 189, 200, 234, 266 and 371 of S-adenosylmethionine synthetase MAT to obtain a series of mutants with improved enzyme activity, wherein the specific enzyme activity of I189V / V266H and V266H / N371R is increased by more than 10 times relative to the parent. The yields of S-adenosylmethionine synthesized by whole cells of recombinant bacteria expressing mutants I189V / V266H / N371R, V266H / Q234N / N371R and I189V / V266H / Q234N / N371R all reach 1550 mg / L or more. The provided enzyme mutants have broad application prospects in the production of S-adenosylmethionine and the construction of genetically engineered microorganisms for S-adenosylmethionine.

The invention discloses a high-efficiency lysine decarboxylase mutant and an application of the high-efficiency lysine decarboxylase mutant in synthesis of pentamethylene diamine. A series of mutants including a single mutant (such as N218G, T222V, C244P and the like), a double mutant and a three mutant are obtained by carrying out multi-site mutation on wild type lysine decarboxylase (SEQ ID NO.2) from Klebsiella grimontii. The catalytic efficiency of the mutant is remarkably improved, and the activity of the mutant is improved by 5.0-10.2 times compared with that of a wild type enzyme. According to the method disclosed by the invention, the substrate conversion rate of 99% or above can be realized within 2 hours through an optimized process of constructing an expression vector and a genetically engineered bacterium, inducing expression of lysine decarboxylase and synthesizing 1, 5-pentanediamine by utilizing a whole-cell catalysis technology. Compared with a traditional chemical method and a natural enzyme method, the method disclosed by the invention has the advantages of simplified process, high catalytic efficiency, low production cost and the like, and is suitable for producing bio-based 1, 5-pentamethylene diamine and nylon 56 salt.

The invention discloses a mutant with improved catalytic activity of S-adenosylmethionine synthetase and application of the mutant, and belongs to the technical field of biological enzyme engineering. According to the present invention, the site 189, the site 234, the site 266 and the site 371 of the S-adenosylmethionine synthetase MAT are subjected to site-specific combinatorial mutation to obtain a series of mutants with improved enzyme activity, the I189V / V266H improvement is the most obvious, and the specific enzyme activity is 3.5833 + / -0.1373 U.mg <-1 >, which is improved by 1353.08% compared to the parent WT; and for a whole-cell catalysis system, the yield of S-ademetionine synthesized by the mutant I189V / V266H / Q234N / N371R reaches 1751.01 mg / L, and the increase is most obvious. The enzyme mutant provided by the invention has a wide application prospect in the production of S-adenosylmethionine and the construction of genetic engineering microorganisms of S-adenosylmethionine.

The invention provides an application of inositol monophosphate in an enzyme catalysis reaction system for preparing inositol. The invention also provides a preparation method of the inositol, the starch is used as a substrate, glucan phosphorylase, glucose phosphate mutase, inositol-3-phosphate synthase and inositol monophosphate are added as enzyme catalysts to catalyze the substrate to generate the inositol, the inositol monophosphate is derived from Archaeoglobus fulgidus, the amino acid sequence is shown as SEQ ID NO: 12, or the amino acid sequence is shown as SEQ ID NO: 1, or the amino acid sequence is shown as SEQ ID NO: 2, or the amino acid sequence is shown as SEQ ID NO: 3, or the amino acid sequence is shown as SEQ ID NO: 4, or the amino acid sequence is shown as SEQ ID NO: 5, or the amino acid sequence is shown as SEQ ID NO: 6. The inositol monophosphate is derived from Thermococcus kodakarensis, and the amino acid sequence of the inositol monophosphate is as shown in SEQ ID NO: 13; or the inositol monophosphate is derived from Pseudothermotoga lettinae, and the amino acid sequence of the inositol monophosphate is as shown in SEQ ID NO: 14. Inositol-3-phosphate synthetase and inositol monophosphate with good performance are screened, high-concentration starch is efficiently catalyzed to be converted into inositol by a one-pot method in a whole-cell feeding mode, and NAD < + > and other coenzymes do not need to be used. Under a 60L reaction system, 200g / L of corn starch is catalyzed, the unit yield of the prepared inositol reaches 161g / L, and the method has a good industrial application prospect.

The invention relates to the technical field of agricultural biology, in particular to a fusion P450 enzyme mutant, a method for improving VD3 catalytic activity and a method for generating 25 (OH) VD3 through whole cells. The invention constructs a fusion P450 enzyme VK1-CYP116B46-L21 and a self-sufficiency fusion P450 enzyme mutant with improved activity, wherein the self-sufficiency fusion P450 enzyme mutant is used for catalyzing vitamin D3 to synthesize calcifediol; vD3 is taken as a substrate, glucose, a cosolvent and a wet thallus induced by recombinant escherichia coli for simultaneously expressing fusion P450 enzyme and glucose dehydrogenase are added, and the highest yield of 25 (OH) VD3 within 24 hours after catalytic reaction can reach 3.26 g / L; whole cells are directly used as a catalyst, enzyme purification is not needed, glucose dehydrogenase is introduced, and glucose is used as a substrate to regenerate a cofactor NAD (P) H, so that addition of expensive cofactors is avoided, the production cost is reduced, and industrial production is facilitated.

The invention provides a photovoltaic module and a photovoltaic system. The photovoltaic module comprises a first bypass module, and a first battery string group and a second battery string group which are connected in parallel; each of the first battery string group and the second battery string group comprises two battery strings which are connected in parallel, each battery string comprises a plurality of quartered battery pieces which are connected in series, and each quartered battery piece is a quarter battery piece formed by cutting a whole battery piece; the photovoltaic module also comprises a second bypass module, and a first battery unit and a second battery unit which are connected in parallel. The first end of the first battery unit and the first end of the second battery unit are both connected with the output end of the second bypass module, and the second end of the first battery unit and the second end of the second battery unit are both connected with the input end of the second bypass module. According to the photovoltaic module provided by the embodiment of the invention, the battery piece is arranged to be the quarter battery piece formed by cutting the whole battery piece, so that the internal power loss of the battery piece can be reduced, and the output power of the photovoltaic module can be improved.

The invention discloses a method for preparing butanediamine and spermidine from whole cells, and belongs to the field of bioengineering. According to a rational copolymerization modification strategy, a meridian interface and a latitudinal channel interface of arginine decarboxylase are subjected to rational modification respectively or simultaneously, and a series of mutants are obtained. The optimal mutant AdiA H729D / E467K / H736E, which is subjected to double-interface synergistic modification, disclosed by the invention, keeps high activity in the whole neutral-alkaline range of pH (Potential of Hydrogen) of 7.0 to 9.0. The optimal pH of the arginine decarboxylase mutant is increased, the enzyme activity stability in a neutral pH range is improved, the arginine decarboxylase mutant is more suitable for the condition requirements of industrial microbial fermentation, and a foundation is laid for efficient synthesis of butanediamine. The spermidine yield is up to 153.3 mg / L by using the mutant to catalyze the whole cell.

The invention relates to a photovoltaic module and a production method of the photovoltaic module, and a whole battery piece can be cut into four split battery pieces, including two edge pieces with chamfers and two middle pieces without chamfers; the photovoltaic module comprises a plurality of battery strings, each battery string comprises a plurality of first battery sections and a second battery section, each first battery section sequentially comprises an edge piece, a middle piece, a middle piece and an edge piece, the second battery section comprises two edge pieces and three middle pieces, or the second battery section comprises three edge pieces and two middle pieces. In the invention, the battery string is provided with the edge pieces and the middle pieces, so that waste caused by the fact that the middle pieces are not used can be reduced when the battery string is assembled. The number of the edge pieces and the number of the middle pieces in one battery string are only one, so that the using number of the edge pieces and the using number of the middle pieces in one battery string are balanced, and when the battery strings are assembled, the remaining number of the edge pieces and the remaining number of the middle pieces are small.

The invention provides a method, device and system for evaluating the effect of intervening small molecules by tumors and a storage medium, and relates to the technical field of bioinformatics, the method comprises the following steps: obtaining a first transcriptome representation of a tumor cell population before target small molecule intervention and a second transcriptome representation of a normal tissue cell population corresponding to the tumors; inputting the first transcriptome representation and the condition vector into a prediction model to obtain a third transcriptome representation; calculating a first distance and a second distance; an intervention effect is evaluated based on a comparison of the first distance and the second distance. According to the method, the influence of the drug on the transcriptome of the whole cell population is efficiently predicted, and the distance between the transcriptome and the health state is quantitatively compared, so that a set of brand new standard for improving the evaluation target from the traditional'killing cell 'to'reversing disease state' is established, and an objective decision basis is provided for developing more accurate drugs.

The invention discloses recombinant escherichia coli for producing sucrose phosphorylase as well as a construction method and application of the recombinant escherichia coli, and belongs to the technical field of biological engineering. The sucrose phosphorylase is constructed, the amino acid sequence of the sucrose phosphorylase is shown as SEQ ID NO.11, a recombinant escherichia coli BdSP-L341V / L343F / V346P for expressing the sucrose phosphorylase is constructed, the sucrose phosphorylase expressed by recombinant bacteria or whole cells of the recombinant bacteria are used for carrying out catalytic reaction, and efficient production of ascorbyl glucoside can be realized. The invention also provides a method for producing ascorbic acid glucoside, the catalytic reaction is carried out at normal temperature and normal pressure, toxic and harmful organic solvents are not used, and the pollution to the environment is reduced; the whole catalytic process is a one-step reaction, has the advantages of high conversion rate, simple purification step and simple process, can better save the production cost, and has wide industrial application prospects.

The invention discloses a nitrilase mutant and application thereof in nicotinic acid biosynthesis, and belongs to the technical field of enzyme engineering. Through mutation design based on sequence fitness, the nitrilase mutant with improved nitrilase activity, thermal stability and soluble expression level is constructed, and the half-life period of the mutant D1F4 at 50 DEG C can reach 123.40 + / -5.94 min. The high-performance mutant obtained through construction is used for preparing nicotinic acid through whole-cell catalysis of 3-cyanopyridine, the final concentration of the product can be remarkably increased, and the final concentration of the product after 520 min of reaction can reach 2.21 M.

The present application relates to the technical field of fermentation engineering, and provides an engineered Escherichia coli for producing uroporphyrin as well as a construction method and application thereof.The present application uses Escherichia coli to express porphyrin synthase of thermophilic bacteria, performs whole-cell catalysis of 5-ALA to synthesize uroporphyrin under high-temperature conditions, and completely shields endogenous regulation; further, the Escherichia coli is wrapped by COF material to prevent the loss of enzymes in the cell recovery process; and a protein scaffold based on dockerin-cohesin is constructed to further improve the yield of uroporphyrin III.The present application creates a brand-new uroporphyrin high-temperature whole-cell catalysis process, realizes the efficient production of uroporphyrin, and provides a basis and idea for the industrial production of uroporphyrin.

The invention discloses a diketopiperazine heterodimer as well as a biosynthesis method and application thereof, and belongs to the technical field of bioengineering. The biosynthesis method of the diketopiperazine heterodimer comprises the following steps: S1, culturing a recombinant cell containing P450 dimerization enzyme or a mutant thereof, and performing induced expression to obtain a whole-cell culture; and S2, adding a cyclic dipeptide substrate containing tryptophan into the whole-cell culture, carrying out a catalytic reaction, and separating and purifying the obtained product to obtain the diketopiperazine heterodimer. According to the invention, the P450 dimerization enzyme or the mutant thereof is used for catalyzing the biosynthesis of the tryptophan-containing diketopiperazine into the diketopiperazine heterodimer with different regioselectivity / stereoselectivity, the biosynthesis method is green and environment-friendly, the efficiency is high, and the variety of the diketopiperazine heterodimer is greatly expanded.

The utility model relates to the field of culture solution concentration detection, in particular to an on-line protein concentration detection device for expanding a concentration range. The device comprises a first injection pump, a selector valve, a container assembly, a dilution and detection assembly and an air filter, the selector valve is provided with a public port and six selection ports uniformly distributed around the public port, and the public port is communicated with one of the six selection ports; a buffer ring is communicated between the first injection pump and the common port of the selection valve; the container assembly comprises a calibration standard liquid container, a first cleaning liquid container, a second cleaning liquid container and a culture container; the dilution and detection assembly comprises a three-way valve, a dilution assembly and a detection assembly respectively communicated with two ends of the three-way valve, and a sample reserving valve communicated with the output end of the detection assembly. According to the utility model, the detection concentration range is expanded to 6.5 orders of magnitude, the requirement of the protein measurement concentration range from extremely low concentration to extremely high concentration in the whole cell culture process is met, and the measurement accuracy and sensitivity are high.

Disclosed are systems and methods for producing renewable alcohols by fermentative processes using cell lysate or a combination of cell lysate and whole cells, as well as the cell lysate itself. The disclosure also provides processes and systems for converting renewable alcohols to transportation fuels, such as, gasoline, jet fuel, and diesel fuels.

The present application relates to a kind of whole cell catalytic synthesis N-acetyl-trans-4-hydroxyproline method, belong to biological catalysis technical field.The present application is constructed by mutating acyltransferase and heterologous expression gene engineering bacteria, successfully realized using whole cell catalytic synthesis N-acetyl-trans-4-hydroxyproline, avoids the problem of enzyme instability, reduces the separation cost of enzyme and product.On this basis, the present application improves the yield of N-acetyl-trans-4-hydroxyproline by optimizing catalytic time, cell addition amount, the type and addition amount of additive, and the yield reaches 239mg / L.The present application is a kind of N-acetyl-trans-4-hydroxyproline preparation method with lower cost, lower equipment demand, more suitable for industrial production.

This application discloses an embedded whole-cell biosensor, its fabrication method, and its application in machine learning-assisted mercury ion detection, belonging to the field of sensor materials and detection technology. This sensor encapsulates *E. coli* expressing green fluorescent protein (GFP) in a polyacrylamide / hyaluronic acid (PAAM / HA) hydrogel matrix, enabling highly selective and sensitive detection of mercury ions. It effectively eliminates interference from competing metal ions and can be completely regenerated through EDTA-2Na treatment, allowing for repeated use without performance loss. It maintains a stable fluorescence response for up to three weeks, possesses excellent biocompatibility and biodegradability, minimizing the risk of secondary contamination, and facilitates rapid on-site analysis.

The application discloses a 17beta-hydroxysteroid dehydrogenase mutant, an engineering bacterium and application, and uses the 17beta-hydroxysteroid dehydrogenase mutant to biotransform methyl diketone as a substrate to prepare nandrolone. The 17beta-hydroxysteroid dehydrogenase is 17beta-hydroxysteroid dehydrogenase (17beta-HSDcl) from a fungus Cochliobolus lunatus, and the mutant is a single mutant in which histidine His at the 164th position is mutated into valine Val, a single mutant in which threonine Thr at the 151st position is mutated into alanine Ala, or a double mutant in which the 164th position and the 151st position are jointly mutated. The application uses pET28a as an expression plasmid, realizes heterologous expression of the 17beta-HSDcl mutant in E.coli BL21 (DE3), and through 24h whole cell transformation of the engineering bacterium, the nandrolone yield of the single mutant H164V, the single mutant T151A and the double mutant H164V / T151A is 1.27 times, 1.30 times and 1.34 times that of before mutation, respectively. The application provides a basis for industrialized production of nandrolone by microorganisms.

The invention provides a beta-glucosidase mutant from Paenibacillus phyllosphaerae, and a method for efficiently preparing rare ginsenoside F2 by using an enzyme method and a whole-cell method, and particularly provides a beta-glucosidase mutant from Paenibacillus phyllosphaerae and a method for efficiently preparing rare ginsenoside F2 by using a beta-glucosidase mutant from Paenibacillus phyllosphaerae. The method comprises the following steps: engineering-modifying beta-glucosidase by utilizing computer-aided design, constructing a mutant library, carrying out primary screening and secondary screening to obtain two high-activity mutants Q7D and G189A, constructing a combined mutant Q7D / G189A, transforming the combined mutant Q7D / G189A into genetically engineered bacterium escherichia coli for expression, and producing F2 by utilizing a whole-cell method. Finally, the highest yield of 18.01 g / L is achieved after the reaction is carried out for 10 h in a 5 L fermentation tank and is 6.82 times that of a shake flask, and the purity of F2 reaches up to 82.20% after the reaction is carried out for 24 h finally. The invention not only provides an efficient solution for large-scale production of rare saponin F2, but also provides a transferable framework for designing and engineering diversified glycoside hydrolase in customized biological catalysis.

The invention discloses an amylosucrase mutant and application thereof in synthesis of alpha-arbutin, the mutant is obtained by mutation of an amino acid sequence of amylosucrase derived from coprophilobacterium mediterranei, and the amino acid sequence of the mutant is shown as SEQ ID NO.4. The invention further discloses a preparation method of the amylosucrase mutant. Compared with a wild strain, the catalytic activity, the temperature stability and the substrate tolerance of the amylosucrase mutant disclosed by the invention are remarkably improved; the recombinant bacteria constructed by using the recombinant bacteria can be used as a whole-cell catalyst to efficiently catalyze a substrate to synthesize alpha-arbutin in a reaction system containing hydroquinone. Therefore, the amylosucrase mutant disclosed by the invention has a good application prospect.

The present application relates to the technical field of frame design, and particularly relates to a frame design method and system for assembled whole-cell intercell, which comprises the following steps: obtaining demand information and a model library, wherein the demand information comprises multiple frame models of intercell, and the demand function, demand size and bearing requirement of each frame model; the model library comprises multiple component models; determining the connection sequence of each frame model according to the demand function, determining the component model combination of the corner of each frame model in turn according to the connection sequence, determining the component model combination in each frame model and the corresponding connection sequence according to the demand size, and obtaining the component model sequence of intercell; determining the geometric characteristics and material of the component model in the component model sequence according to the bearing requirement, and generating the frame structure of intercell; the present application can provide a quick and flexible design scheme according to the individualized customization demand of intercell.

The application provides a myo-inositol-3-phosphate synthase mutant, which is obtained by mutating a myo-inositol-3-phosphate synthase with an amino acid sequence as shown in SEQ ID NO: 4 at positions 55, 57 and 273 respectively. The application also provides a preparation method of myo-inositol. The inventors have screened a wild-type myo-inositol-3-phosphate synthase and a myo-inositol monophosphatase with good performance, which can be used in cooperation with a glucan phosphorylase and a glucose phosphate mutase to catalyze starch to generate myo-inositol more efficiently. The myo-inositol-3-phosphate synthase mutant is applied to in-vitro non-fermentation biosynthesis of myo-inositol, combined with myo-inositol monophosphatases E1 and E5, and in a way of feeding whole cells, so that starch can be converted into myo-inositol in a one-pot method, without using NAD + coenzymes, and has a good industrial application prospect.

The present application relates to the field of agricultural biotechnology, in particular to fusion P450 enzyme mutants, methods for improving the catalytic activity of VD3, and methods for producing 25(OH)VD3 by whole cells, wherein a fusion P450 enzyme VK1-CYP116B46-L21 and a self-sufficient fusion P450 enzyme mutant with improved catalytic activity for synthesizing calcidiol from vitamin D3 are constructed; using VD3 as a substrate, adding glucose, a cosolvent, and a recombinant Escherichia coli expressing the fusion P450 enzyme and glucose dehydrogenase after induction, the maximum yield of 25(OH)VD3 can reach 3.26 g / L within 24 h after the catalytic reaction; directly using whole cells as catalysts without purifying enzymes, introducing glucose dehydrogenase to regenerate cofactor NAD(P)H using glucose as a substrate, avoiding the addition of expensive cofactors, reducing production costs, and being conducive to industrial production.

The invention belongs to the technical field of biological catalysis, and particularly relates to a glycosyl transferase mutant and application thereof in catalytic synthesis of rebaudioside M. Engineering bacterium whole cells or broken enzyme liquid for co-expressing a glycosyl transferase G1 mutant, a glycosyl transferase C1 mutant and sucrose synthase SUS is used as a catalyst, Reb A is used as a substrate, sucrose is used as a glycoside donor, Reb M is synthesized under mild conditions, the space-time yield of the generated Reb M is up to 3.33 g / L / h, and the method has the advantages of being high in space-time yield, convenient to purify, green, environmentally friendly and the like, and is suitable for industrial production. The industrial application value is extremely high.

The present invention discloses the construction and application of a recombinant Gluconobacter oxydans, belonging to the fields of genetic engineering and whole-cell catalysis. The present invention heterologously expresses an epoxide hydrolase from Sphingomonas in Gluconobacter oxydans, and simultaneously utilizes the alcohol and aldehyde dehydrogenases bound to the membrane of Gluconobacter oxydans itself to synthesize R-mandelic acid in a one-step process using styrene oxide as a substrate. The present invention combines the transcriptome data of Gluconobacter oxydans, screens 7 strong promoters using green fluorescent protein as a reporter gene, and determines the strongest promoter P for expressing the epoxide hydrolase gene. 12780 , ultimately significantly increasing the yield of R-mandelic acid.

This invention belongs to the field of synthetic biology and microbial engineering, and discloses a chemical-biological method for preparing the isopentenyl bibenzyl compound 2-isopentenyl-3,3',4',5-tetrahydroxybibenzyl (NPB-1575) which has anti-ischemic stroke activity. The specific disclosed method includes: (1) chemically synthesizing the substrate dihydropiperidine; (2) constructing an engineered Escherichia coli strain based on the isopentenyl utilization pathway, co-expressing hydroxyethylthiazol kinase, isopentenyl phosphokinase, isopentenyl pyrophosphate isomerase and specific isopentenyl transferase, and efficiently synthesizing the isopentenyl donor; (3) using this strain to catalyze dihydropiperidine in whole cells, the yield in a 200L fermenter can reach 2.54g / L, which is nearly 40 times higher than the existing method; (4) obtaining NPB-1575 with a purity >98.5% by macroporous adsorption resin and normal / reversed phase chromatography and recrystallization. This method uses readily available raw materials, involves simple steps, is environmentally friendly, and yields high purity, laying the foundation for the development of NPB-1575 as a new drug for ischemic stroke and showing significant application potential.

The application discloses a kind of recombinant Pichia pastoris for indirectly surface display PETase protein, comprising: (1) 3×IM7-SED1 fusion protein is expressed heterologously in Pichia pastoris GS115, and constructs IM7 yeast.(2)CL7-PETase fusion protein is expressed heterologously in Escherichia coli BL21 (DE3), and constructs CL7-PETase protein.(3)IM7 yeast and CL7-PETase protein are combined, and the surface display of PETase protein on Pichia pastoris is realized.The construction method of indirect surface display used in the application overcomes the disadvantage of insufficient expression of direct surface display system, and compared with free enzyme, has the characteristics of high stability, easy separation and recovery, controllable continuous operation, simple process, and the surface display enzyme is different from traditional physical or chemical immobilization method.For PET rigid substrate, surface display enzyme can more fully and effectively contact with substrate, maximum catalysis substrate, and can be used as whole-cell catalyst in the application of PET plastic degradation.