75results about How to "Little loss of enzyme activity" patented technology

The invention provides an immobilized transaminase obtained via immobilizing recombined transaminase on sodium alginate. Firm bonding of the immobilized transaminase is realized; enzyme activity loss is less; separation is simple; recycling can be realized for a plurality of times; asymmetric conversion process cost is low; reaction conditions are mild; the immobilized transaminase is friendly to the environment; operation is simple; industrial enlarged production is convenient to realize; and industrial application prospect is promising.

The invention discloses a separation and purification method and an immobilization method of papain, and a product thereof. The separation and purification method comprises the following steps: 1, obtaining an initial crude enzyme solution through dissolving a raw material containing papain, removing insoluble substances, and adjusting the protein concentration to 10-20mg / ml; 2, mixing the initial crude enzyme solution with polyethylene glycol, an inorganic salt and water, dissolving, and carrying out phase separation after all component are uniformly mixed, wherein the content of the initial crude enzyme solution is 30-40%, the content of polyethylene glycol is 10-30%, the content of the inorganic salt is 10-25%, and the pH value is 5.5 to 6.5; and 3, taking a polyethylene glycol phase obtained after the phase separation, and recovering the papain through an ion exchange method. The immobilization method is that papain is immobilized in the polyethylene glycol phase which is enriched in papain. The separation and purification method allows good biological compatibility, simple operation steps, and mild operation conditions to be realized, processes to be easily amplified, less enzyme activity loss of products and no organic solvent residual to be achieved, and immobilization steps to be substantially simplified.

The invention discloses a feed compound enzyme capable of improving animal appetite and a preparation method of the feed compound enzyme, and belongs to the technical field of preparation of an enzyme preparation. The feed compound enzyme is scientifically compounded from fragrant malt enzyme, feeding complex enzyme, acidic xylanase, cellulose, beta-glucanase, amylase, phytase, Chinese herb extracts, a protective agent and an activating agent, wherein the feed complex enzyme contains protease, mannose, alpha-galactase and pectinase, and is strong in heat stability and pH stability. By adopting the prepared feed compound enzyme, safe digestive enzyme is provided for beasts and birds, the digestion burden is effectively relieved, the utilization rate and the growth rate of the raw materials are improved, the environment is protected, an enjoyable natural malt fragrance is brought about for the feed, the livestock and poultry appetites are increased, meanwhile, proper activating agent can fully exert the efficacy of an enzyme preparation under the equal conditions, the adding amount of the enzyme preparation is saved, the guarantee period of the complex enzyme preparation is prolonged by the Chinese herbal medicine extract, the immunity of beasts and birds is improved, and the multi-purpose effect of the enzyme is achieved.

The invention discloses aspergillus niger capable of highly yielding a compound enzyme for a feed and an application thereof, and belongs to the technical field of microbial fermentation. The strain of the aspergillus niger specifically is aspergillus niger DM-18 which is collected in the China Center for Type Culture Collection with the collection number of CCTCC M2013541. A crude enzyme which is obtained through culture medium optimization and fermentation for 72-96 hours contains a plurality of kinds of enzymes, wherein the activity of protease is 6500U / ml, the activity of mannase is 1500U / ml, the activity of alpha-galactase is 1200U / ml and the activity of pectase is 1000U / ml. The optimum pH value for the activity of each enzyme in the compound enzyme ranges from 2 to 7, and is suitable for the digestion and absorption environment of the gastrointestinal tract of the animal; the compound enzyme for feed can be widely applied to the feeds for beasts and birds, is capable of reducing the antinutritional factors and increasing the digestibility, and has excellent economic benefits; simultaneously, the compound enzyme is also advantageous for protecting the economic environment and promoting healthy development of the animal husbandry.

The invention discloses a method for producing 1,5-pentanediamine through immobilized lysine decarboxylase. The method comprises the following steps of connecting a chitin binding domain (ChBD) gene to the N end of a lysine decarboxylase gene (CadA) to construct a fusion protein; fermenting the fusion protein to obtain a crude lysine decarboxylase enzyme solution; adding chitin into the crude enzyme solution to obtain immobilized lysine decarboxylase; finally, enabling the obtained immobilized lysine decarboxylase to participate in a decarboxylation reaction of L-lysine to prepare 1,5-1,5-pentanediamine. According to the method, the specific affinity effect of the substrate chitin and the fusion protein is skillfully utilized to adsorb the lysine decarboxylase, the cost of the immobilizedcarrier chitin is low, the immobilization efficiency is high, the activity stability of enzymes is high, and meanwhile, the procedure of protein purification can be omitted through specific affinity adsorption. The provided method achieves repeated production of 1,5-1,5-pentanediamine and can reduce the production cost, simplify the separation procedure of downstream products and enzymes and achieve remarkable economic benefits.

The invention discloses a technological method for removing glucose in an isomaltooligosaccharide product by using multiple immobilized enzymes. The technological method is used for realizing multiple enzyme separated immobilization by taking calcium carbonate as a template and combining bionic silicification and bionic bonding thoughts on the basis of a layer-by-layer self-assembly technology so as to remove the glucose in the isomaltooligosaccharide product. The technological method is simple in preparation process, mild in condition and little in enzyme activity loss; the prepared immobilized enzymes are used for removing the glucose in the isomaltooligosaccharide product at a high removal rate up to over 80%, and are relatively high in repeated utilization ratio; a carrier is cheap and easy to obtain.

The invention discloses a bromelain stabilizer and a preparation method and application thereof, and relates to the technical field of biology. The bromelain stabilizer is prepared from the followingcomponents in parts by weight: 0.015 to 0.13 part of reductant, 0.002 to 0.07 part of metal ion chelating agent, 0.01 to 0.09 part of organic carboxylate, 0.05 to 0.15 part of preservative, and 0.001to 0.02 part of vitamin. The bromelain stabilizer has the advantages that the effect of protecting enzyme activity is obvious, the loss of enzyme activity is reduced, the half-life period of enzyme isshortened, the usage amount is small, the cost is low, and the like. The preparation method has the advantages that the operation is simple, and the preparation method is suitable for industrializedproduction; the bromelain stabilizer can be directly added inr the process of storage of enzyme solid powder or production of liquid enzyme, and the application range is broad.

The invention discloses a catfish feed compound enzyme and a preparation method thereof. The preparation method of the catfish feed compound enzyme is characterized by taking nutritional requirement of the catfish and the water environment as the basis, optimizing the raw material formula, combining digestion characteristics of the catfish and scientifically compounding a wine making yeast culture material with functional characteristics such as high nutrition performance, high biological activity, high oxidation resistance and the like, a calcium fruit extract capable of effectively supplementing calcium, iron and soluble fiber, providing powerful embedding effect and prolonging the quality guarantee period of the feed compound enzyme, wormwood seed powder capable of obviously improving anti-freezing effect and stability of the feed compound enzyme, improving water resistance and glossiness of the catfish feed and reducing powder content in the feed, a palatable agent capable of greatly improving palatability and digestion rate of the feed, and wheat malt flour capable of providing rich nutrient materials, biological active materials and plant enzyme sources to finally obtain the catfish feed compound enzyme capable of obviously enhancing digestion rate and parturition performance of the catfish, reducing the feed coefficient, preventing water pollution and maintaining high water quality.

The invention discloses a lysozyme with covalent modification through medium and long fat chain acyl-free sophorolipid derivatives (DSL-C12) and a modifying method and application of the lysozyme. The modifying method comprises the following steps that firstly, active esters of sophorolipid derivatives are dissolved in DMSO, then a NaHCO3 aqueous solution of lysozyme is added, a condensation reaction is carried out under the stirring condition, and a reaction mixture is obtained after the reaction is finished, wherein the sophorolipid derivatives are carboxylic acid type medium and long fat chain sophorolipid; secondly, deionized water and a phosphate buffer solution are adopted in sequence to carry out dialysis on the mixture obtained in the first step, obtained dialysate is subjected to centrifugation separation, and the modified lysozyme is obtained. The modified lysozyme can effectively suppress the activity of gram-positive bacteria and can also remarkably suppress the activity of gram-negative bacteria, so that the antibacterial spectrum of natural lysozyme is expanded, and the lysozyme can serve as a multifunctional food preservative.

The invention discloses a green preparation method of high-purity galactooligosaccharide. The green preparation method comprises the following steps of fermenting preparation of yeast whole cell containing beta-galactosidase endoenzyme, permeabilizing treatment of yeast whole cell by an ethanol solution, preparation of galactooligosaccharide by permeabilized yeast cell catalyzing lactose (purpose of yeast I), and obtaining of high-purity galactooligosaccharide (purpose of yeast II) by using yeast whole cell reaction to purify a crude product of galactooligosaccharide. The green preparation method has the advantages that the permeable yeast cell and the yeast whole cell can be repeatedly utilized, so that the effect of one yeast, two purposes is realized in the green cycling preparation of the high-purity galactooligosaccharide; the purity of the obtained high-purity galactooligosaccharide can reach 99% to the highest degree, the technology is simple, no harmful matter is added, the required equipment cost is low, and the high-purity galactooligosaccharide is suitable for being widely and industrially popularized.

The invention discloses a lysozyme with covalent modification through acyl-free sophorolipid derivatives and a modifying method and application of the lysozyme. The modifying method comprises the following steps that firstly, active esters of acyl-free sophorolipid derivatives are dissolved in DMSO, then a NaHCO3 aqueous solution of lysozyme is added, a condensation reaction is carried out under the stirring condition, and a mixture with covalent modification is obtained after the reaction is finished, wherein the sophorolipid derivatives are carboxylic acid type acyl-free sophorolipid; secondly, deionized water and a phosphate buffer solution are adopted in sequence to carry out dialysis on the butter solution system obtained in the first step, obtained dialysate is subjected to centrifugation separation, and the lysozyme with covalent modification is obtained. The modified lysozyme can effectively suppress the activity of gram-positive bacteria, can also remarkably suppress the activity of gram-negative bacteria, and can serve as a multifunctional food preservative.

The invention discloses a fermentation liquor treatment method for increasing the stability of pullulanase, and belongs to the technical field of enzyme engineering and fermentation engineering. The fermentation liquor treatment method is characterized in that pullulanase fermentation liquor sourcing from recombinant bacteria-bacillus amyloliquefaciens BF7658 / pUC980-BdP is treated by using 10*fermentation liquor treatment solution, and the enzyme activity stability of the pullulanase in the treated fermentation liquor is obvious higher than that of untreated fermentation liquor. According to the fermentation liquor treatment method for increasing the stability of the pullulanase, disclosed by the invention, in a post-extraction stage of a technology for preparing the pullulanase by taking the recombinant bacteria-bacillus amyloliquefaciens BF7658 / pUC980-BdP as a strain for fermentation, the loss of enzyme activity can be reduced.

The invention relates to a method for extracting and purifying superoxide dismutase (SOD), and in particular relates to a method for extracting and purifying SOD from saccharomyces cerevisiae. The method comprises the following operation steps: collecting bacteria, homogenizing bacteria, preparing a crude enzyme fluid, carrying out ultrafiltration, implementing chromatography and desalting. The method disclosed by the invention can be used for effectively purifying non-modified SOD protein and keeping the original activity of the SOD; and through a pyrogallol oxidation method, the specific activity of the purified high-purity SOD can reach up to 15000U / g and the entire process is relatively high in yield; and the method is simple to operate and capable of achieving industrial mass production.

The invention relates to a production method of a pesticide residue fast detection card based on horse serum cholinesterase. The method comprises precipitating and setting cholinesterase in horse serum through a salting-out method, carrying out purification through centrifugation, redissolution and dialysis to obtain cholinesterase satisfying the requirements, carrying out dilution according to the activity of the cholinesterase, adjusting pH and a salt ion concentration, adding a stabilizer into the solution to obtain a pesticide residue fast detection card enzyme work solution, pressing twocircular filter papers on a support substrate at a high temperature, adding a cholinesterase working solution and a substrate working solution on the two filter papers drop by drop, carrying out airing and carrying out plastic packaging to obtain the pesticide residue fast detection card. The pesticide residue fast detection card has good sensitivity, stability, repeatability, reproducibility, simplicity, rapidness, intuitiveness and low cost and is suitable for rapid screening of pesticide residues on fruits and vegetables.