431 results about "Immobilized enzyme" patented technology

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 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 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 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 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.

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 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.

The invention discloses the technical field of anthocyanin extraction, and particularly relates to a method for extracting anthocyanin in blueberries by using a sodium alginate immobilized enzyme. According to the method, blueberries are used as a raw material, sodium alginate is used as a carrier to immobilize cellulase, and process conditions for extracting anthocyanin are optimized, including sodium alginate concentration, enzymolysis temperature and time, enzyme concentration and enzyme proportion. The immobilized enzyme is applied to an anthocyanin extraction process, when the temperature is 50 DEG C and the reaction time is 3h, the yield of anthocyanin is improved by 18.7% compared with that of free enzyme, and the activity of the immobilized enzyme still keeps 75% or above after the immobilized enzyme is repeatedly used for five times. In addition, the sodium alginate immobilized enzyme shows good thermal stability.

The invention relates to the technical field of enzyme engineering, and particularly discloses a preparation method of immobilized sucrose phosphorylase (SPase) with low cost and high stability. According to the method, epoxy resin is synergistically modified through gallic acid (GA) and a polyethyleneimine-chitosan copolymer (PEI-CS), a covalent bond-hydrogen bond-ionic bond ternary cross-linked network is formed, and efficient immobilization of SPase is achieved. The preparation method comprises the following steps: preparation of a PEI-CS copolymer, preparation of a GA-PEI-CS modification liquid, modification treatment of epoxy resin, immobilization of SPase and determination of enzyme activity. The prepared immobilized enzyme has high enzyme activity retention rate (96.5%), wide temperature and wide pH stability (high activity is kept at 60 DEG C and pH 4.0-10.0), long reuse life (82.1% of enzyme activity is kept after 50 times of reuse) and low cost (26.7 yuan / kg), and can be widely applied to the fields of food industry, cosmetic industry and biological pharmacy.

The invention belongs to the technical field of bioengineering, and particularly relates to collagen tripeptide as well as a preparation method and application thereof. The method comprises the following steps: carrying out depolymerization treatment on a raw material containing collagen to construct a magnetic immobilized enzyme; by utilizing the magnetic immobilized enzyme, raw materials subjected to depolymerization treatment are subjected to enzymolysis at a certain temperature, pH and reaction time, and with the assistance of a magnetic field, rapid separation and cyclic utilization of the immobilized enzyme can be realized. And finally, carrying out enzyme deactivation, solid-liquid separation and ultrafiltration to obtain the collagen tripeptide with GPH content of more than or equal to 59wt.%, and compared with the existing collagen tripeptide, the collagen tripeptide has higher GPH content. The preparation method is simple in process, easy and convenient to operate, low in cost, capable of achieving mass production and suitable for industrialization, and has remarkable practicability and economic benefits.

The invention belongs to the technical field of natural product extraction and enzyme engineering, and particularly relates to a method for extracting red pomelo polyphenol based on an enzyme method. The method aims at solving the problems of high cost and the like caused by easy inactivation and difficult recovery of enzymes in most red pomelo extraction processes. Waste such as pericarp and pomelo seeds generated by red pomelo processing are used as carbon sources, a biochar material with a hierarchical porous structure is prepared through programmed heating carbonization activation, pectinase, cellulase and naringinase are immobilized by adopting a spatial zoning sequential immobilization strategy and then react with the red pomelo, and the biochar material with the hierarchical porous structure is prepared. The immobilized enzyme is rapidly recovered through magnetic separation to realize repeated utilization of the enzyme, and finally red pomelo polyphenol powder is obtained through multi-step treatment, so that recycling is realized, and the yield of polyphenol extracted by an enzyme method is improved.

The invention relates to the technical field of gene engineering, in particular to a D-psicose-3-epimerase mutant and application of the D-psicose-3-epimerase mutant in synthesis of psicose. According to the present invention, the 59th site, the 106th site and the 188th site of the wild type D-psicose-3-epimerase derived from Brevibacillus thermophilus (Brevibacillus thermophilus) are subjected to simultaneous mutation to obtain the D-psicose-3-epimerase mutant, such that the efficiency of producing D-psicose by using fructose as the raw material is significantly improved, the reaction of catalyzing 500 g / L fructose to produce D-psicose is performed for 4 h, and the yield of the D-psicose is significantly improved; the conversion rate is up to 36.5%; according to the present invention, the coexpression binding enzyme strain is constructed by coupling glucose isomerase, such that the intermediate transfer efficiency and the enzyme stability are improved, the reaction for producing D-psicose through catalysis of 500 g / L glucose is performed for 6 h, and the conversion rate can achieve 30.5%; and the activity of the immobilized enzyme can still be kept at 80% after the immobilized enzyme is repeatedly used for 10 batches.

The invention provides a composite sodium alginate-based aerogel immobilized enzyme carrier and an application thereof. The preparation method comprises the following steps: dispersing sodium alginate and oxidized sodium alginate in deionized water, adding starch and nanocellulose, stirring in a boiling water bath until the starch and nanocellulose are completely dissolved, and cooling to room temperature to obtain a mixed solution; adding a beta-galactosidase solution, and uniformly stirring to obtain an enzyme-containing mixed solution; slowly dripping into a metal ion solution at a constant speed for primary hardening; adding a CaCl2 solution for secondary hardening, and separating to obtain gel microspheres; immersing into a potassium phosphate buffer solution containing polydopamine nanoparticles; freezing and drying; and carrying out heat-moisture treatment. Sodium alginate is used as a substrate material and has good biocompatibility, resistant starch is added in the preparation process, the stability of the aerogel immobilization carrier is improved, and the aerogel immobilization carrier shows a round and full skeleton structure after being freeze-dried to form a supporting effect; and a dynamic dual-network design is adopted, so that the self-repairing capability is provided.

The invention discloses zero-lactose milk containing galactooligosaccharide and a preparation method of the zero-lactose milk, and belongs to the technical field of dairy products. By means of the synergistic effect of the immobilized lactase and the acerola cherry powder extract, efficient hydrolysis of lactose is achieved, the lactose content is reduced to 0.1-0.5 g / 100 mL, meanwhile, 1.0-2.5 g / 100 mL of galactooligosaccharide is generated, and the lactase is especially suitable for people with lactose intolerance to drink. The preparation method comprises the following steps: pasteurizing the raw milk at 60-65 DEG C for 20-40 minutes, and then cooling; adding 0.01 to 0.3 percent of immobilized lactase and 0.001 to 0.1 percent of acerola cherry powder extract under the condition of 20 to 50 DEG C, and stirring and reacting for 10 to 60 minutes; then heating at the temperature of 80-120 DEG C for 5-20 minutes for enzyme deactivation; performing ultrasonic homogenization (200 to 500W, 20 to 70kHz, 10min), cooling and filling; and finally, carrying out ultrahigh pressure sterilization for 5 minutes at 500 MPa and 28 DEG C to ensure that the product is sterile. The stability and the repeated utilization rate of the enzyme are improved through the immobilized enzyme technology, and due to the addition of the acerola cherry powder extract, the product is endowed with natural oxidation resistance while the lactose is synergistically hydrolyzed.

The invention provides Yixinshu granules and a preparation method thereof, and belongs to the technical field of medicines. Ginseng, astragalus membranaceus, radix ophiopogonis, hawthorn, salvia miltiorrhiza, schisandra chinensis and ligusticum wallichii are subjected to immobilized enzyme enzymolysis and enzyme-assisted fermentation, a product is filtered, an ionic liquid solid-phase extraction agent is added, carbon dioxide is introduced, stirring adsorption, filtering, solid desorption and drying are conducted, extract is prepared, the extract, maltodextrin and stevioside are evenly mixed, granulation and drying are conducted, and the Yixinshu granules are prepared. The Yixinshu granules prepared by the invention are simple in preparation method, wide in raw material source, easy to realize industrial application, relatively low in cost and high in patient compliance, have the characteristics of quick dissolution, quick absorption, high bioavailability and the like, have the effects of tonifying qi and restoring pulse, promoting blood circulation to remove blood stasis and nourishing yin and promoting salivation, and have a wide application prospect.

The invention relates to the technical field of odor-absorbing towels, in particular to a bacillus subtilis-based biological enzyme odor-absorbing towel and a preparation method thereof.The bacillus subtilis-based biological enzyme odor-absorbing towel comprises the following four layers: a surface layer, a breathable anti-reverse-osmosis non-woven fabric or nano-silver coating material, the pore diameter of the surface layer is smaller than or equal to 0.1 micron, and the surface layer is used for gas adsorption and liquid blocking; the biological enzyme filter membrane layer is formed by loading bacillus subtilis spores (greater than or equal to 108 CFU / g) and immobilized enzymes (lipase and protease) by a sodium alginate / chitosan composite hydrogel membrane; the specific surface area of the adsorption layer is larger than or equal to 1200 m < 2 > / g, the H2S adsorption capacity of the adsorption layer is larger than or equal to 200 mg / g, and the adsorption layer is used for pre-adsorbing high-concentration sulfides; the bottom layer is a microporous PE leakage-proof film, and the humidity is maintained at 60%-80% RH. According to the invention, peculiar smell molecules can be effectively degraded, liquid reverse osmosis can be prevented, and good air permeability and humidity regulation and control capability can be realized.

The invention relates to the technical field of bioengineering, in particular to a process for continuously producing nicotine based on immobilized enzyme. The immobilized microbial agent comprises a composite carrier, an engineering strain and an immobilized auxiliary agent, in the process for continuously producing nicotine based on immobilized enzyme, amine oxidase of an engineering strain is subjected to site-specific modification, so that spatial structure deformation when the amine oxidase is combined with a carrier is reduced, and a three-dimensional network structure of hydroxyethyl chitosan-guar gum composite microspheres in the composite carrier is matched to provide an adaptive microenvironment; the activity loss of enzyme molecules caused by steric hindrance or structural change is reduced; in the immobilization auxiliary agent, gallic acid and an enzyme molecule sulfydryl form a coordinate bond to maintain an active center conformation, glutaraldehyde and polyethyleneimine enhance the binding stability through a crosslinking effect and charge regulation, and the maintaining effect of enzyme activity during continuous production is improved, so that the enzyme activity loss in the immobilization process is reduced, and the immobilization efficiency is improved. The stability of the enzyme in long-term continuous reaction is enhanced.

A method for immobilizing beta-glucanase based on a rice husk-sodium alginate composite carrier belongs to the field of enzyme engineering and biological materials, and comprises the following steps: 1) crushing and sieving rice husks; 2) mixing rice husks and sodium alginate according to a mass ratio of 1: 3-1: 6, and performing ultrasonic dispersion and magnetic stirring to form a carrier solution; (3) adding beta-glucanase into the carrier solution, and reacting for 35-50 minutes at the temperature of 30-35 DEG C; and 4) dropwise adding the enzyme-carrier mixed solution into a calcium chloride solution for curing and forming, and washing and drying to obtain the immobilized enzyme particles. By optimizing the ratio of the composite carrier, when the mass ratio of the rice husks to the sodium alginate is 1: 4, the catalytic activity of the prepared immobilized enzyme under unit mass is obviously higher than that of other ratio groups. According to the method, agricultural waste rice hulls are used as main raw materials, the cost is low, the process is simple, the prepared immobilized enzyme is high in activity, and a new way is provided for industrial application of beta-glucanase.

The invention discloses a method for synthesizing D-psicose by multi-enzyme immobilized cascade catalysis of sucrose, and belongs to the technical field of food production. The method provided by the invention comprises the following steps: respectively immobilizing sucrose invertase, glucose isomerase and epimerase by utilizing protein affinity immobilization purification magnetic beads to prepare immobilized enzyme, carrying out enzymatic reaction by taking sucrose as a substrate, and converting the sucrose into D-psicose step by step. Experimental results show that the method provided by the invention can effectively convert cane sugar, glucose and fructose which are easy to absorb into D-psicose which is difficult to absorb; after the enzymatic reaction, the immobilized enzyme can be effectively recovered through rapid separation and can be reused, so that the production cost is saved. The invention provides a low-cost and high-efficiency production method for the production of D-psicose, and the method has a wide application prospect.

The invention belongs to the technical field of enzyme engineering and gene engineering, and particularly relates to a recombinant immobilized enzyme, an expression gene thereof and application of the recombinant immobilized enzyme in production of macrocyclodextrin. According to the preparation method, SpyTag and SpyCatcher peptides are fused to the N end of isoamylase and the N end of 4-alpha-glucanotransferase respectively, the 4-alpha-glucanotransferase modified by the SpyTag and the isoamylase modified by the SpyCatcher are obtained, and after spontaneous isopeptide bonds are formed between the SpyTag and the SpyCatcher, the self-assembled macrocyclodextrin production enzyme cluster is obtained. The obtained macrocyclodextrin production enzyme cluster forms an enzyme aggregate with a three-dimensional structure under the traditional glutaraldehyde-mediated catalytic action, namely the recombinant immobilized enzyme. The recombinant immobilized enzyme disclosed by the invention can be repeatedly utilized, is simple and convenient to operate, is easy to separate a converted product, and can be applied to industrial production of the macrocyclodextrin.

The invention discloses an immobilized enzyme with a Pickering emulsion stabilizing effect and a preparation method and application thereof. The preparation method comprises the following steps: adding shellac into an alkaline solution, stirring until the shellac is dissolved, preparing an aqueous solution, adjusting the pH value of the solution to 6-8, fully stirring to uniformly disperse shellac particles, and drying to obtain shellac nano-particle powder; the preparation method comprises the following steps: dispersing shellac nano-particle powder in water or a buffer solution, adding EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride) and NHS (N-hydroxysuccinimide), then adding lipase, and carrying out a coupling reaction to obtain the shellac nano-particle immobilized enzyme. The natural nanoparticle immobilized enzyme prepared by the invention not only can stabilize Pickering emulsion, and the emulsion can realize reversible emulsification-demulsification circulation under the stimulation of acid-base or gas, but also can be used for constructing a phytosterol ester efficient synthesis reaction system.

The present invention relates to novel enzyme nanoparticles capable of converting methane into methanol, in which key active sites of methane-oxidizing bacteria are fused with each other and expressed on a protein that can be self-assembled in cells to form nanoparticles, and specifically to enzyme nanoparticles including a protein having methane monooxygenase (MMO) activity and active sites of the methane oxidase, a method for production thereof, a recombinant microorganism into which a nucleic acid encoding the protein and the active site of the methane oxidase is introduced, and immobilized enzyme nanoparticles including the enzyme nanoparticles loaded on a carrier.

The invention provides a traditional Chinese medicine composition for improving spleen and stomach health and a preparation method thereof. The traditional Chinese medicine composition is prepared from the following raw materials in parts by weight: 25 to 30 parts of rhizoma dioscoreae, 15 to 20 parts of rhizoma atractylodis macrocephalae, 8 to 15 parts of fructus aurantii, 10 to 15 parts of red dates, 8 to 12 parts of liquorice root, 10 to 15 parts of inulin, 6 to 10 parts of fructus amomi and 5 to 8 parts of cassia twig. The lauric acid modified fenugreek gum (LA-FG) is used as an emulsifier and an immobilized enzyme carrier to construct a water-oil two-phase enzymolysis system, so that the content of effective active ingredients in the traditional Chinese medicine composition, the product stability and the bioavailability are remarkably improved. In addition, the traditional Chinese medicine composition can effectively improve the gastric emptying rate and the small intestine propulsion rate, the level of motilin and anti-inflammatory factors IL-10 is improved, and the effect of improving spleen and stomach health is achieved through multi-target-point synergism. The method successfully breaks through double limitations of a traditional process and an existing scheme, effectively considers volatile oil protection, efficient enzymatic conversion and system stability, and provides a new path for promoting technical upgrading of the traditional Chinese medicine industry.