566 results about "Immobilized enzyme" patented technology

The invention discloses a PBAT (poly (butylene adipate-co-terephthalate)) composite material containing nano encapsulation enzyme as well as a preparation method and application thereof. The PBAT composite material is prepared from the following components in percentage by mass: 50 to 90 parts of PBAT resin, 0 to 40 parts of filler and 0.01 to 20 parts of nano encapsulation enzyme. The preparation method comprises the following steps: firstly synthesizing the nano encapsulation enzyme, and then mixing the nano encapsulation enzyme, the PBAT resin and the filler, extruding, and carrying out hot press molding or curtain coating and film blowing. The method is characterized in that 1) the nano encapsulated enzyme has more excellent thermal stability than other immobilized enzymes, and the biological activity of the enzyme can be effectively maintained after high-temperature heat treatment; and 2) as the biological activity of the enzyme is effectively reserved, the PBAT composite material containing the nano encapsulated enzyme has higher environmental degradation speed than pure PBAT or a PBAT composite material containing free enzyme, and the environmental degradation speed can be reflected in various conditions such as aqueous solution and industrial compost.

The invention belongs to the technical field of grease modification and lipid deep processing, and particularly relates to a method for enriching n-3 polyunsaturated fatty glyceride by an enzymic method. According to the method, alkyl-modified hollow mesoporous silica spheres are used as an immobilized enzyme carrier and an emulsifier, grease rich in n-3 polyunsaturated fatty acid is used as a raw material in a stable Pickering emulsion system, saturated fatty acid and monounsaturated fatty acid are selectively hydrolyzed by lipase, and polyunsaturated fatty glyceride is enriched. The method has the characteristics of fast reaction, high yield, wide substrate application range and reusability of the immobilized enzyme, and the content of polyunsaturated fatty acid in the polyunsaturated fatty glyceride reaches 58.05-90.53%.

The invention discloses a high-stability hydroxysteroid dehydrogenase mutant, a co-immobilized enzyme construction method and application. According to the invention, a site-directed mutant library is constructed based on computer-aided design, and mutants with significantly improved thermal stability and greatly improved catalytic efficiency compared with wild type mutants are obtained through screening; meanwhile, a co-immobilized enzyme construction method based on electrostatic adsorption and chemical crosslinking is established, the hydroxysteroid dehydrogenase mutant and lactic dehydrogenase are co-immobilized, the co-immobilized enzyme can still keep high activity under high substrate concentration, and the conversion rate is still maintained to be 90% or above after 30 batches of co-immobilized enzyme are repeatedly used. And an important foundation is laid for industrial application of the hydroxysteroid dehydrogenase.

The invention relates to screening and application of a Candida antarctica lipase B mutant. Specifically, the Candida antarctica lipase B mutant provided by the invention is obtained by carrying out rational design and directed evolution combined strategy mutation on the basis of a wild Candida antarctica lipase B gene sequence, and the amino acid sequence of the mutant is shown as SEQ ID NO.3. The invention also relates to a preparation method of the Candida antarctica lipase B mutant. The mutant has higher enzyme activity and thermal stability, the hydrolytic catalytic activity of the mutant is improved to 2.1 times of the original hydrolytic catalytic activity, and the half-life period of the mutant enzyme at 50 DEG C is prolonged by 4 times. On the basis, pichia pastoris is used as a host to express the mutant, and a strain with hydrolytic activity improved by 52% is obtained through high resistance screening. The lipase is prepared into an immobilized enzyme to be used in a synthetic reaction of chlorogenic acid derivatives, the highest conversion rate of chlorogenic acid reaches 74% in 24 hours, and the immobilized enzyme has a good industrial application prospect.

The invention provides a novel nano material as well as an immobilized enzyme and application thereof, and relates to the fields of biotechnology and application, material synthesis and application, water environment treatment and environmental protection. The particle size of the nano material is 2-30 microns, and the aperture of the surface is 2-30 nm; the solid nanomaterial is prepared by the following method: adding an alkali solution into a metal salt solution, fully mixing, then adding a ligand aqueous solution, fully reacting, and then separating to obtain the solid nanomaterial. When the material is used for immobilizing enzyme, the particle size of the obtained immobilized enzyme is 2-20 microns, and the aperture of the surface is 1-15 nm; the preparation method comprises the following steps: mixing an enzyme with a ligand aqueous solution, then adding the mixture into a metal salt mixed solution, and separating a solid product. The nano material has excellent biocompatibility and mild synthesis conditions, can protect the reaction activity of the enzyme under harsh conditions such as high temperature, acid and alkali, and improves the recycling capability and storage capability of the enzyme.

The invention relates to the field of immobilized enzymes, in particular to immobilized lipase with graft-modified amino resin as a carrier and a preparation method thereof.The method comprises the steps that firstly, the amino resin is modified through the oxidative auto-polymerization characteristic of tannic acid, and first modified amino resin is obtained; and modifying the first modified amino resin by using fatty amine as a hydrophobic modifier to obtain second modified amino resin. Then lipase is fixed on the second modified amino resin through physical adsorption, the lipase is subjected to interfacial activation on an amphiphilic interface on the second modified amino resin, and a part of lipase is covalently bound with quinonyl in an activated state, so that the immobilized lipase with high activity and stability is obtained. The method is easy to operate, green and non-toxic, the prepared immobilized lipase is good in enzyme activity and stability, and the method can be used for preparing the immobilized lipase on a large scale, can be applied to the field of food and has industrial application potential.

The invention belongs to the technical field of food lipid and processing, particularly discloses a one-pot enzymatic cascade degumming and deacidification method for grease and application, and particularly relates to a method for performing cascade degumming and deacidification on multiple kinds of grease, generating functional lipid, improving the quality of the grease and maintaining the flavor of the grease. According to the method, phospholipase is immobilized through the porous carrier and is successfully applied to enzymatic cascade degumming and deacidification, and degumming, deacidification or cascade degumming and deacidification can be carried out on different raw materials according to requirements. Moreover, the prepared grease is rich in functional lipid components, the flavor is efficiently reserved, the oxidation stability is improved, the nutritional quality is improved, the immobilized carrier is cheap and easy to obtain, the immobilized enzyme can be repeatedly used for multiple times and is remarkably superior to free enzyme, and the industrial application potential is huge.

The invention provides a method for preparing high-purity phosphatidylserine by a batch enzyme catalysis method based on dynamic choline removal, and belongs to the technical field of enzymatic reaction. According to the method disclosed by the invention, in a reaction system for preparing phosphatidylserine, a byproduct choline is selectively adsorbed by adopting resin. Choline in a reaction system is removed in real time through the integrated adsorption separation module, the enzyme inhibition problem is solved, and meanwhile, the PC conversion rate is larger than or equal to 98% and the PS purity is larger than or equal to 96% in combination with the immobilized enzyme circulation technology; the enzyme can be reused for more than or equal to 20 times (activity retention is more than or equal to 90%); and the choline residual concentration is less than or equal to 0.5 mM (an inhibition threshold value or less).

The invention discloses an enzyme immobilization method based on charge directed crosslinking, and belongs to the technical field of enzyme immobilization. The method sequentially comprises the following steps: reacting an enzyme with a modifier containing an anionic group to generate an electronegative modified enzyme; dissolving a protonated amino carrier in an acidic buffer solution to form a first solution, and dispersing a dissociation anion group-containing carrier and a modification enzyme in an alkaline buffer solution to form a second solution; mixing the two solutions, and constructing a gel network immobilized enzyme through electrostatic crosslinking; and finally, strengthening the gel network by using a multivalent metal ion solution. Directional anchoring of the enzyme in the gel is achieved through charge matching, the network stability and the enzyme microenvironment are synchronously optimized in combination with metal ion coordination, use of a covalent cross-linking agent is avoided in the whole process, conformation damage of an enzyme active center is avoided, the activity retention rate, the operation half-life period and the substrate mass transfer efficiency of the immobilized enzyme are remarkably improved, and the immobilized enzyme has good application prospects. The method is suitable for efficient immobilization of industrial enzymes such as beta-glucosidase, and has high biocompatibility and industrial potential.

The invention discloses a method for producing D-pantoic acid by immobilizing D-pantoic acid lactone hydrolase fusion protein, and belongs to the technical field of biology. The insoluble seed pumpkin acidic polysaccharide PPFS3 is extracted from an agricultural waste, namely seed pumpkin pulp, meanwhile, a fusion protein constructed by connecting a carbohydrate binding module and D-pantoic acid lactone hydrolase is provided, and the fusion protein and the seed pumpkin acidic polysaccharide PPFS3 have specific binding capacity; a simple, convenient and low-cost immobilized enzyme and recombinant protein purification method can be established. The formed immobilized fusion protein can be used for efficient and continuous production of D-pantoic acid.

The invention discloses a gastrodia elata polypeptide extraction process, and belongs to the technical field of polypeptide extraction. According to the method, gastrodia elata cell membranes are broken through acetone pretreatment, so that protein and lipid are dissociated, trimethylsilyl ether passivates active groups, immobilized enzyme decomposes cellulose and adipose tissues through normal-temperature enzymolysis, a protein stabilizer prevents oxidation and inhibits enzyme activity, differential pressure extraction is combined with a sodium pyrophosphate buffer solution, polypeptide is promoted to be dissolved out, and activity is maintained; the high extraction rate of the gastrodia elata polypeptide and low-active group destructiveness are realized. Reaction sites and binding force are increased by epoxy groups on the surface of an immobilized enzyme carrier prepared by modifying corn starch, enzyme molecules are stable and appropriate due to good biocompatibility, enzyme molecule conformation is optimized through covalent binding, a rigid structure is enhanced, enzyme activity is kept at a high level for a long time, continuous and efficient enzymolysis is performed in gastrodia elata polypeptide extraction, and the gastrodia elata polypeptide extraction efficiency is improved. Compared with the traditional free enzyme, the gastrodia elata polypeptide enzyme has the advantages that the enzyme use cost is reduced, the enzyme consumption and waste generation are reduced, and an efficient and economical scheme is provided for gastrodia elata polypeptide extraction.

The invention discloses a ganoderma lucidum extraction method based on a reusable magnetic enzyme. The ganoderma lucidum extraction method comprises the following steps: S1, preparing a nanoscale amination modified Fe3O4-SiO2 magnetic composite carrier; s2, on the basis of the amination modified Fe3O4-SiO2 magnetic composite carrier, cellulase is added, and a magnetic immobilized enzyme buffer solution is obtained; s3, the ganoderma lucidum sporocarp is put into a magnetic immobilized enzyme buffer solution to be subjected to enzymolysis, extraction and filtration, effective components of ganoderma lucidum are obtained, and magnetic immobilized enzyme is recycled for repeated utilization; according to the method, the magnetic nanoparticles are modified, so that the surfaces of the magnetic nanoparticles have specific active groups, meanwhile, the magnetic response advantage of an inorganic magnetic material is reserved, the nanoscale amination-modified Fe3O4-SiO2 magnetic composite carrier is prepared, enzyme molecules can be directly anchored on the surfaces of the magnetic nanoparticles, and enzyme activity is improved. The immobilized enzyme can be conveniently recycled from a reaction system, so that the cost of an enzyme preparation can be reduced, and the enzyme activity stability can be improved.

The invention provides a method for converting D-fructose in jujubes into D-psicose by immobilized enzyme, jujube juice containing D-psicose and application, and particularly belongs to the technical field of beverage preparation. The method for converting the D-fructose in the jujubes into the D-psicose by the immobilized enzyme comprises the following steps: mixing the immobilized D-psicose-3-epimerase with jujube juice, carrying out sugar conversion, centrifuging and discarding precipitate to obtain jujube juice containing the D-psicose; the nucleotide sequence of the gene for coding the D-psicose-3-epimerase is as shown in SEQ ID NO. 1 (sequence identifier number 1). According to the method disclosed by the invention, the D-fructose in the jujubes can be effectively converted into the D-psicose.

The invention discloses immobilized lipase based on bifunctional silicon dioxide as well as a preparation method and application of the immobilized lipase. Hydrophobic modification and covalent modification are performed on the surface of mesoporous silicon dioxide to obtain a bifunctional silicon dioxide carrier; the hydrophobic modification is any one of methylation modification, octylation modification, octadecyl alkylation modification, esterification modification and bromopropylation modification. The dual-functionalized silicon dioxide carrier is used for immobilization of lipase, and the prepared immobilized lipase can be used for production of biodiesel. The immobilized lipase provided by the invention is mild in enzyme reaction condition, good in biocompatibility, relatively high in enzyme activity, and excellent in stability and repeatability. In addition, by changing the ratio of the covalent modifier to the hydrophobic modifier, the catalytic activity and stability of the immobilized enzyme and the biodiesel yield are remarkably improved.

The invention discloses an advanced treatment agent for textile printing and dyeing wastewater and a treatment method. The advanced treatment agent comprises a component A and a component B, the component A comprises modified graphene oxide and an enzyme treatment agent; the component B comprises magnesium aluminum silicate, hydroxyapatite, hydroxypropyl methyl cellulose and chitosan, and the hydroxyapatite is coated with the magnesium aluminum silicate to form a core-shell structure. By adopting a modified graphene oxide immobilized enzyme structure, harmful components in water can be effectively adsorbed, so that the effect of greatly improving sewage purification is achieved, and meanwhile, the adsorption effect of the harmful components can be further improved by matching with aluminum-magnesium silicate coated hydroxyapatite, hydroxypropyl methyl cellulose and chitosan; meanwhile, bonding with the modified graphene oxide is beneficial to agglomeration and flocculation of substances, so that the flocculation capacity is improved, and floc separation is facilitated.

The invention belongs to the field of biological catalysis, and particularly relates to an enzyme immobilization carrier, an immobilized enzyme and a preparation method and application of the enzyme immobilization carrier, the enzyme immobilization carrier and the immobilized enzyme, the enzyme immobilization carrier comprises aminated magnetic Fe-Ni nanoparticles, the enzyme immobilization carrier has good stability and is easy to separate and recycle, and the enzyme activity can still be kept at 90% or above after the enzyme immobilization carrier is recycled 12 times.

The invention relates to the technical field of industrial microorganisms and food industry, and discloses an immobilized enzyme composition and application thereof in efficient preparation of rebaudioside M. The immobilized enzyme composition provided by the invention comprises immobilized UDP-glycosyl transferase UGT and immobilized UDP-glycosyl transferase UGT76G1 according to a mass ratio of (1 to 2): (1 to 3). By adopting the immobilized enzyme composition disclosed by the invention, the rebaudioside A can be synergistically and efficiently promoted to be converted into the rebaudioside M, and the conversion rate is up to 85% or above and can be up to 97% at most; the working efficiency of the enzyme is remarkably improved, and the rebaudioside M is efficiently prepared; meanwhile, the enzyme is good in stability and can be repeatedly used for at least five times, and the catalytic efficiency is still higher than 95%. The method has great popularization and application values.

The invention discloses a method for preparing artificial bear gall powder through double enzymes, the artificial bear gall powder and application of the method, and belongs to the technical field of biology. The method comprises the following steps: respectively immobilizing two enzymes, and filling the two immobilized enzymes into a column or a reactor according to a ratio. The method can reasonably and effectively control the proportion of the amount of two enzymes participating in the reaction, so that the enzymatic reaction is effectively controlled, and the stability and consistency of the batch-to-batch conversion reaction are ensured. And after the enzymatic reaction is finished, the immobilized enzyme can be recycled in manners of centrifugation, filtration, magnetic separation and the like and is fixed according to the enzymatic reaction requirement, so that the immobilized enzyme can be recycled for multiple times, the use amount of the enzyme is saved, and the use efficiency of the enzyme is improved. The method provided by the invention is strong in operability, good in repeatability and easy in linear amplification, the ratio of TUDCA to TCDCA in the obtained product can reach 1.33 or above, and the method is suitable for industrial production of artificial bear gall powder.

The invention discloses a method for digesting an extracellular matrix by an immobilized enzyme and application, and relates to the technical field of biology. The method comprises the following steps: (1) performing decellularization treatment on tissues to obtain an extracellular matrix; (2) dispersing the surface functionalized microspheres in a buffer solution, adding a coupling agent, mixing, and collecting the activated microspheres; (3) dispersing the activated microspheres in a buffer solution containing pepsin, mixing, and collecting immobilized enzyme microspheres; and (4) crushing the extracellular matrix, dispersing the crushed extracellular matrix in a solution, adding the immobilized enzyme microspheres for digestion, and separating and removing the immobilized enzyme microspheres after digestion is completed. According to the method provided by the invention, the enzymolysis of the immobilized enzyme on the extracellular matrix is realized by adopting a proper microsphere particle size and a proper zeta potential. According to the method disclosed by the invention, the residual quantity of free enzyme is relatively small, so that the biological safety of the extracellular matrix material is improved.

The invention discloses potato starch nano-carrier immobilized lipase and a preparation method thereof, and relates to the technical field of biological catalysis. The immobilized lipase comprises a lipase and a carrier, and the lipase is immobilized on the carrier; the carrier is potato starch modified magnetic nanoparticles. The immobilized lipase provided by the invention takes the magnetic potato starch nanoparticles as a carrier and has the advantages of being green and environment-friendly and easily available in materials, and the lipase is successfully immobilized on the magnetic nanoparticles by using the potato starch and the traditional glutaraldehyde as cross-linking agents. The method not only improves the activity and stability of the immobilized enzyme, but also has good biocompatibility and safety. By optimizing parameters such as potato starch dosage, enzyme concentration and immobilization time, the obtained immobilized enzyme shows excellent storage stability and repeated utilization rate. In addition, the method provides reference for preparation of other high-performance immobilized enzymes.

The invention discloses an SAM hydrolase mutant and application thereof, the specific activation effect of halogen anions (F <->, Cl <->, Br <-> and I <->) on SAM hydrolase (containing MJ1651 wild type and mutant) is found for the first time, and the active sequence of the SAM hydrolase is F <-> > I <-> > Br <-> = Cl <->. According to the method, 400 mM of halide salt is added into a reaction system, so that the catalytic efficiency is improved in a breakthrough manner; the yield of wild type enzyme adenosine is improved by 20-300% (optimally, an F-system); the yield of the mutant R89C is soaring up by nearly 6 times under the action of KF; the activity of the immobilized enzyme is still more than 90% after the immobilized enzyme is repeatedly used for 5 times. The method is easy and convenient to operate, green production is achieved with water as the solvent (three wastes are reduced by 90%), the comprehensive cost is reduced by 41%-80 / kg, and an efficient solution is provided for industrial biological manufacturing of antiviral drug intermediates and the like.

The invention discloses a magnetic immobilized enzyme and a preparation method and application thereof in preparation of chitosan oligosaccharide, the immobilized enzyme comprises a carrier and an enzyme loaded on the carrier, the carrier is a magnetic nanoparticle modified double-hole silicon dioxide nanoparticle, the double-hole silicon dioxide nanoparticle simultaneously contains a plurality of macropores and a plurality of micropores, and the macropores and the micropores are uniformly distributed on the carrier. The aperture of the large hole is 20-40nm, the aperture of the small hole is 2-5nm, and the magnetic immobilized enzyme has strong magnetism, is more rapid and convenient to recover, has good reusability, is simple and convenient to operate, has a wide application prospect, and is suitable for industrial preparation of chitosan oligosaccharide.

The invention relates to a microneedle patch, a preparation method thereof and a blood glucose colorimetric detection method, and belongs to the technical field of biomedicine. The microneedle patch comprises a needle tip layer and a backing layer, the needle tip layer is a methacrylated natural biopolymer matrix in which immobilized enzyme is uniformly distributed, and the backing layer is a methacrylated natural biopolymer matrix in which a chromogenic substrate is uniformly distributed, the immobilized enzyme is composed of a zinc-based imidazoline metal organic framework MAF-7 carrier and a natural enzyme loaded in the framework. The immobilized enzyme with double-enzyme activity is loaded into the needle tip, the spatial distance of the cascade catalytic reaction is limited in the metal organic framework, the mass transfer efficiency is high, the reaction is rapid, the natural enzyme is encapsulated in the metal organic framework MAF-7, and the stability of the enzyme is enhanced; according to the method, color development is carried out by firstly extracting the interstitial fluid and then dropwise adding the color development substrate, the color development effect is obvious, and the time is shorter.

The invention discloses an efficient continuous PET (polyethylene terephthalate) degradation process based on a membrane method technology, which comprises the following steps: mixing an immobilized enzyme compound, a PET raw material to be degraded and a glycine buffer solution to form a reaction solution for degradation, then constructing a'continuous reactor 'by using two size screening membranes, performing primary separation by using an ultrafiltration membrane or a microfiltration membrane, and performing secondary separation by using an ultrafiltration membrane or a microfiltration membrane. A nanofiltration membrane or a reverse osmosis membrane is adopted for secondary separation of the degradation product, automatic separation of the degradation product and a reaction system and automatic purification of the degradation product are achieved, and then the enzymatic degradation efficiency and the product recovery efficiency are improved. Through the construction of the continuous reactor, the automatic PET degradation is realized, so that the costs in the aspects of labor, time, economy and the like are remarkably saved. The undegraded PET and a small amount of exfoliative enzyme can be circulated back to the reaction kettle after being intercepted by the size screening membrane, and the process not only can promote full contact between the undegraded PET and the hydrolase, but also can reduce the loss of the enzyme in the degradation process.

The utility model discloses a magnetic immobilized enzyme recycling device, which relates to the field of immobilized enzyme recovery and comprises a reaction tank, a filler screen is arranged on the reaction tank, and the aperture of the filler screen is larger than the diameter of immobilized enzyme; the device further comprises a collecting mechanism, and the collecting mechanism is located on the movement stroke of the immobilized enzyme. According to the magnetic immobilized enzyme recycling device provided by the utility model, the aperture of the filler screen is set to be larger than the diameter of the immobilized enzyme, so that the airflow interaction amount of the filler screen is increased, and the circulation efficiency of substances is accelerated; and an independent collecting mechanism is designed, so that the immobilized enzyme flowing out of the sieve pores can be independently collected, and cyclic utilization is realized.

Recipe for a double microencapsulated powder, characterized in that the recipe comprises the following components in parts by weight: 5-60 parts by weight of core material of group A, 5-40 parts by weight of core material of group B, 5-16 parts by weight of protein shell material, 3-19 parts by weight of polysaccharide shell material, 0.1-2 parts by weight of immobilizing enzyme, 1-10 parts by weight of filler, 1-4 parts by weight of pH regulator and 0-2 parts by weight of antioxidant.

The invention discloses preparation of immobilized alpha-glucosidase based on a magnetic metal organic framework (MOF) and application of the immobilized alpha-glucosidase in screening of natural enzyme inhibitors. According to the method, ZIF-90 is grafted on the surfaces of Fe3O4 magnetic nanoparticles modified by codeposition of polydopamine and polyethyleneimine, and alpha-glucosidase is synchronously encapsulated in situ in the growth process of the ZIF-90, so that the magnetic MOF immobilized alpha-glucosidase is successfully constructed. On the application level, an in-vitro enzyme inhibition activity evaluation system is constructed, multiple traditional Chinese medicine extracts are selected as research objects, and by means of the characteristic that the magnetic MOF immobilized alpha-glucosidase is easily separated from a reaction system, accurate screening of natural inhibitors or active small molecules is rapidly and efficiently achieved; and a novel screening method is provided for research and development of candidate drugs for diabetes mellitus. The method comprises the following steps: 1, preparing the magnetic MOF immobilized alpha-glucosidase and evaluating the performance of the magnetic MOF immobilized alpha-glucosidase; and 2, the prepared immobilized alpha-glucosidase is used for screening a natural enzyme inhibitor. Based on a magnetic MOF immobilized enzyme technology, the method provided by the invention has the characteristics of rapidness, high efficiency, accuracy, easiness in separation from a reaction system and reutilization of a target receptor alpha-glucosidase, is suitable for screening of alpha-glucosidase inhibitors in complex systems such as traditional Chinese medicines, and has a wide application prospect.

The invention provides an immobilized enzyme as well as a preparation method and application thereof. The immobilized enzyme comprises an enzyme and a carrier for loading the enzyme, wherein the enzyme is alpha-amino acid fatty acyl transferase or polypeptide ligase; the carrier is a polymethacrylate matrix carrier; the polymethacrylate matrix carrier comprises an amino carrier or an epoxy carrier; wherein the amino carrier is an amino carrier modified by a long-chain polymer; the epoxy carrier is an epoxy carrier modified by a long-chain polymer; wherein the long-chain polymer comprises polyethylene glycol (Mw) of 2-8 KDa, polyvinyl alcohol (Mw) of 1.7-31 KDa, polyethyleneimine (Mw) of 1.8-70 KDa, polyacrylamide (Mw) of 50-300 KDa or polylysine (Mw) of 1.6-41 KDa. The immobilized enzyme disclosed by the invention is good in intermolecular dispersity and relatively large in spacing, can efficiently catalyze a substrate to synthesize oligopeptide or polypeptide, and has relatively high substrate conversion rate.

The invention discloses a nicotinic acid immobilized enzyme conversion method, which comprises the following steps: taking wet thalli containing nitrilase, preparing a flocculation clear liquid, passing the flocculation clear liquid through an ultrafiltration membrane, carrying out embedding immobilization to obtain embedded particles not greater than 2mM, and after the embedded particles are hardened, separating and purifying the obtained conversion liquid by adopting a membrane separation method to obtain the nicotinic acid immobilized enzyme. Sequentially carrying out microfiltration, activated carbon decoloration, ultrafiltration, nanofiltration decoloration, acidification crystallization and centrifugation to finally obtain a nicotinic acid finished product. The immobilized enzyme prepared by the method disclosed by the invention can stably exist in nitrile substances, can be repeatedly used for many times, and is high in stability and low in enzyme activity loss rate, and a separated and purified product is free of impurities and high in yield.