213 results about "Alkaline protease" patented technology

The invention relates to the technical field of microorganisms, and particularly discloses a fermentation method of bifidobacterium longum BBMN68 as well as a fermented product, a postbiotic and application of the fermented product. According to the method for fermenting the bifidobacterium longum BBMN68, a fermentation substrate comprises alkaline protease hydrolyzed milk and a pomelo peel extract; the hydrolysis rate of the alkaline protease hydrolyzed milk is 9-11%, and the water-soluble dietary fiber content of the shaddock peel extract is 75-80%; the mass ratio of the alkaline protease hydrolyzed milk to the shaddock peel extract is (10-15): (1-3). The content of active ingredients in the fermented product prepared by the method is high, and after the fermented product is prepared into the postbiotics to be taken, the immune function of an organism can be recovered, immune organ damage is reduced, inflammation is relieved, and intestinal flora is regulated and controlled.

This invention relates to the technical field of deep processing of sturgeon by-products, and particularly to a sturgeon tendon peptide with antioxidant and pancreatic lipase inhibitory activities and its preparation method. The preparation method includes the following steps: mixing sturgeon with water and crushing it to form a first slurry; adding Bacillus licheniformis alkaline protease to the first slurry for a first hydrolysis; adding Bacillus subtilis neutral protease to the first hydrolysate for a second hydrolysis; adding a complex enzyme to the second hydrolysate for a third hydrolysis to obtain a sturgeon tendon hydrolysate; filtering the sturgeon tendon hydrolysate to remove impurities to obtain a filtrate, which is then filtered again to retain polypeptides, thus obtaining the sturgeon tendon peptide; wherein the complex enzyme includes pectinase and amylase. Using this method, a sturgeon tendon peptide with high glycosaminoglycan content can be obtained, which exhibits pancreatic lipase inhibitory activity, antioxidant activity, Staphylococcus aureus inhibitory activity, and prebiotic effects that promote the proliferation of Lactobacillus plantarum and Lactobacillus fermentum.

The present application relates to the technical field of oat bran deep processing, and particularly relates to an oat active polypeptide with GLP-1 secretion promotion, blood sugar reduction and lipid reduction activity, and a preparation method and application thereof.The present application is prepared by adding alkaline protease and ficin for double-enzyme step-by-step hydrolysis after homogenate, enzymolysis and alkali extraction and acid precipitation pretreatment, and then filtering, ultrafiltration desalination and drying, so that the oat active polypeptide with GLP-1 secretion promotion, blood sugar reduction and lipid reduction activity is obtained.The present application is simple to operate, low in equipment requirement, and suitable for industrial large-scale production.The prepared oat active polypeptide has GLP-1 secretion promotion, blood sugar reduction and lipid reduction activity, has a significant inhibitory effect on pancreatic lipase and alpha-glucosidase, has an obvious GLP-1 secretion promotion effect, and has a significant blood sugar reduction and lipid reduction effect.

The invention relates to the technical field of active peptides, in particular to a myocardial active peptide capable of relieving heart failure and protecting heart and a preparation method thereof. The method takes pig hearts as raw materials, and sequentially comprises the following steps: pretreating the pig hearts, adding water, and homogenizing; adding alkaline protease to carry out first constant-temperature enzymolysis; adding neutral protease and flavourzyme to carry out second constant-temperature enzymolysis; then lipase is added for third-time constant-temperature enzymolysis, and enzyme deactivation and cooling are carried out; and finally, adding activated carbon into the enzymatic hydrolysate, filtering with diatomite, and spray-drying to obtain the myocardial active peptide. According to the method, the yield and the purity of the active peptide are remarkably improved through a synergistic process of three-step enzymolysis and activated carbon purification, the obtained product is rich in small molecule peptide with a definite heart protection function, and a new way is provided for high-value utilization of pig heart resources and development of functional products for preventing and treating heart failure.

The invention discloses a preparation method of micromolecular active collagen peptide, which comprises the following steps: (1) cutting fresh leather into fragments, pretreating the leather with a sodium bicarbonate solution, rinsing the leather with deionized water, and refrigerating and storing; (2) mixing papain, bromelain, pancreatin, pepsase, alkaline protease, neutral protease and flavourzyme to obtain a compound enzyme preparation; (3) performing high-pressure steam sterilization on the leather at 110-140 kPa and 120-122 DEG C to obtain leather with the hydrolysis degree of 75-85%, then adding distilled water into the leather to obtain mucilage, then adding a compound enzyme preparation into the mucilage, reacting for 5.5-6.5 hours at the pH of 6.8-7.2 and the temperature of 50-55 DEG C, and then performing enzyme inactivation at the temperature of 85-95 DEG C; and (4) after the reaction system is cooled to room temperature, purifying and centrifuging the reaction system, and taking clarified supernate, thereby obtaining the product. Different animal skins are treated, the proportion of peptide fragments with the molecular weight smaller than 1000 Da of the prepared small-molecule active collagen peptide is larger than or equal to 80%, and the hydroxyproline content is larger than 3%.

This invention relates to the field of chicken gizzard lining processing technology, and particularly to an active polypeptide of chicken gizzard lining, its preparation method, and functional products. The preparation method includes the following steps: mixing chicken gizzard lining powder with water and subjecting it to alkaline heat treatment to form a slurry; sequentially adding Bacillus licheniformis alkaline protease, trypsin, and pepsin to the slurry for three separate hydrolysis processes to obtain a hydrolysate; after enzyme inactivation treatment of the hydrolysate, adding Lactobacillus plantarum for fermentation to obtain a fermentation broth; sterilizing the fermentation broth and then filtering it to obtain a fermentation supernatant; sequentially subjecting the fermentation supernatant to membrane filtration, sterilization, and spray drying to obtain the active polypeptide of chicken gizzard lining. The active polypeptide of chicken gizzard lining prepared by the method of this invention exhibits alcohol dehydrogenase activating activity, AGEs inhibitory activity, albumin denaturation inhibitory activity, lipoxygenase inhibitory activity, pancreatic lipase inhibitory activity, and a beneficial bacteria proliferation promoting effect.

The invention discloses a method for preparing mushroom peptide with salt reducing and salinity increasing capabilities by a controllable biological enzymolysis technology, which comprises the following steps: (1) dissolving edible mushroom powder in water, uniformly stirring, heating and cooling to room temperature; (2) adding cellulase into the solution obtained in the step (1) for enzymolysis, and finishing the first-stage enzymolysis; (3) adding flavourzyme into the enzymatic hydrolysate obtained in the step (2) for enzymolysis, and finishing second-stage enzymolysis; (4) adding alkaline protease into the enzymatic hydrolysate obtained in the step (3) for enzymolysis, and ending third-stage enzymolysis; and (5) carrying out enzyme deactivation on the enzymatic hydrolysate obtained in the step (4), cooling to room temperature, centrifuging, and taking the supernatant to obtain the mushroom protein peptide which is rich in protein peptide and has an obvious salty-increasing effect as the mushroom peptide with salt-reducing and salty-increasing capabilities.

The invention belongs to the technical field of food processing, and relates to a method for preparing low-salt shrimp juice through rapid microbial fermentation. The method comprises the following steps: removing heads of shrimps, preparing meat paste, drying and crushing shrimp shells, and mixing the shrimp shells with the meat paste; carrying out enzymolysis treatment on the meat paste by using alkaline protease, and then carrying out high-temperature enzyme deactivation; mixing the shrimp meat and shrimp shell enzymatic hydrolysate mixture with soybean meal and bran, and sterilizing at high temperature; inoculating a complex microbial inoculant containing lactobacillus plantarum, saccharomyces rouxii, aspergillus oryzae, deep-sea bacillus subtilis and bacillus subtilis to prepare a mold starter, fermenting at 28 DEG C for 30 days, and finally filtering and sterilizing. According to the method disclosed by the invention, the availability of the raw materials is effectively improved, the fermentation period is shortened, efficient fermentation under a low-salt condition is realized, various basic indexes of the obtained shrimp juice product meet national standards, and the shrimp juice product is outstanding in flavor quality and has rich sauce flavor and sweet taste. In addition, the shrimp juice shows good antioxidant stability before and after digestion.

The invention relates to the technical field of gel material preparation, in particular to a bio-based gel material for dangerous chemical leakage disposal and a preparation method thereof.The preparation method comprises the steps that gelatin and deionized water are added into a reaction container, a gelatin solution is obtained under the preset dissolution condition, alkaline protease is added into the gelatin solution for an enzymolysis reaction, and a gelatin solution is obtained; a modified gelatin solution is obtained; the preparation method comprises the following steps: adding a phytic acid-chitosan compound and magnesium-aluminum layered double hydroxide into dispersion equipment, and obtaining a composite inorganic matter dispersion liquid under a preset dispersion condition; adding the modified gelatin solution, the composite inorganic substance dispersion liquid, polyethylene glycol and phase change microcapsules into a mixing reactor, and obtaining a premixed solution under a preset mixing condition; sequentially adding an initiator, a cross-linking agent and tetramethylethylenediamine into the premixed liquid, and performing cross-linking reaction under preset cross-linking conditions to obtain a bio-based gel initial product. The plugging efficiency of the bio-based gel material on dangerous chemical leakage is improved.

The invention provides a preparation method and application of anti-aging and cell-repairing pancreas biological zymolyte, and relates to the technical field of enzyme viscera extracts. The preparation method comprises the following steps: pretreating pancreas, adding water, pulping, boiling, cooling to room temperature, and adjusting the pH value; adding alkaline protease, heating for enzymolysis, dynamically adjusting the temperature and pH during enzymolysis, and inactivating after enzymolysis is finished to obtain enzymatic hydrolysate; adding a reducing agent into the enzymatic hydrolysate, then adding staphylococcus xylosus liquid, carrying out two-stage fermentation, taking supernate after fermentation is finished, and carrying out ultrafiltration concentration; the staphylococcus xylosus bacterial liquid is produced from staphylococcus xylosus YB-12, the staphylococcus xylosus YB-12 is preserved in the China General Microbiological Culture Collection Center on January 3, 2023, and the preservation number of the staphylococcus xylosus YB-12 is CGMCC No. 26373. The finished product prepared by the method is high in stability; meanwhile, the zymolyte can be applied to cell repair or anti-aging.

The invention relates to the technical field of food biology, and discloses an antiviral cubilose polysaccharide active component enriched with bound sialic acid as well as a preparation method and application of the antiviral cubilose polysaccharide active component. The weight-average molecular weight of the cubilose polysaccharide active component is 30-36 kDa, the molecular weight distribution coefficient is 1.1-1.2, the content of bound sialic acid is greater than or equal to 24.0%, and the content of total sugar is greater than or equal to 57.0%. The preparation method comprises the following steps: pretreating a cubilose raw material in a boiling water bath, and sequentially carrying out alkaline protease and neutral protease enzymolysis; carrying out alcohol precipitation on supernate, redissolving, and carrying out papain enzymolysis; and after enzyme deactivation, adjusting the ethanol concentration to 75-85%, precipitating, and drying. According to the method, the cubilose polysaccharide can be efficiently enriched, the combined sialic acid structure of the cubilose polysaccharide is reserved, and the obtained component has the effects of resisting oxidation, inhibiting pathogenic microorganisms and regulating intestinal microecology.

The invention discloses a preparation method of a crocodile polypeptide extract and a beverage, and relates to the technical field of polypeptide extraction and beverage preparation, and the preparation method comprises the following steps: pretreatment of crocodile skin; denaturation treatment: adding a NaHCO3 buffer solution, and treating under a microwave condition; performing ultrasonic pretreatment; carrying out enzymolysis reaction, namely sequentially carrying out primary enzymolysis of alkaline protease and secondary enzymolysis of compounding trypsin and neutral protease; adding composite colloid after enzyme deactivation treatment, wherein the composite colloid comprises flaxseed gum and xanthan gum; centrifuging to take supernate, and carrying out fractional separation through ultrafiltration membranes with the molecular weight cut-off of 500Da and 1000Da; and concentrating and drying to obtain polypeptide powder. According to the method, the polypeptide yield, the beverage stability and the oral bioavailability are improved; finally, the obtained polypeptide is scientifically matched with hyaluronic acid and vitamin C to prepare the beautifying beverage with the effects of remarkably improving skin stains and fine wrinkles and brightening the skin color, and the breakthrough of high-value utilization of crocodile skin resources and product function integration is realized.

This invention discloses a reconstituted rice made from leafy greens and its preparation method. The method involves mixing brown rice flour pretreated with leafy green filtrate with leafy green residue obtained by treatment with sodium hydroxide and alkaline protease. The mixture is then extruded, molded, and air-dried to obtain high-quality, high-nutrient reconstituted rice made from leafy greens. This method solves the problem of nutrient loss in grain raw materials without adding other additives, while synergistically promoting nutrient absorption, improving raw material utilization and nutrient absorption efficiency, and enhancing the nutritional value of the reconstituted rice.

The invention discloses a bacillus constitutive strong promoter and application thereof, and relates to the technical field of biology, and the nucleotide sequence of the promoter is SEQ ID NO: 2. The mRNA transcriptional level of the reporter gene is improved; the method is used for starting a target gene to efficiently express amylase in bacillus subtilis. The method is also used for starting a target gene to efficiently express alkaline protease in bacillus licheniformis. The novel constitutive promoter with enhanced transcriptional activity is developed by taking P43 as a starting template, and under the same host and culture conditions, the absolute level of the constitutive promoter for driving expression of a reporter gene or a target product is higher than that of the current P43 promoter, so that core power is provided for performance improvement of a bacillus cell factory.

The invention relates to the technical field of daily chemicals, in particular to a color-protecting laundry detergent containing plant extracts and a preparation method of the color-protecting laundry detergent. The color-protecting laundry detergent is prepared from the following components in percentage by mass: 12.5 to 18.3 percent of natural anionic surfactant, 6.4 to 9.7 percent of nonionic surfactant, 3.2 to 5.8 percent of plant polyphenol extract, 3.0 to 5.2 percent of fiber affinity natural polymer, 2.1 to 4.0 percent of bio-based chelating aid, 1.8 to 3.5 percent of natural glycoside synergist, 0.9 to 2.3 percent of pH buffering agent, 0.6 to 1.4 percent of antioxidant plant essential oil and the balance of deionized water. The compound protease comprises alkaline protease, neutral protease and papain; the invention aims to solve the technical problems that the existing laundry detergent is poor in color protection effect, insufficient in environmental protection performance and large in damage to fabrics, and provides a laundry detergent product which takes natural plant extracts as core components and has an efficient color protection function.

The application provides a preparation method of non-denatured type II collagen for increasing bone density and improving bone elasticity, and belongs to the technical field of biotechnology. The application adopts EDTA-citric acid buffer containing beta-mercaptoethanol to decalcify cartilage, adopts supercritical CO2 extraction technology to defat, adopts alkaline protease and collagenase II to perform matrix directional enzymolysis, and performs gradient digestion; then three-phase centrifugal separation is adopted to separate non-denatured type II collagen, and biomimetic H column chromatography purification is adopted, so that non-denatured type II collagen with high extraction rate, high purity and high structural integrity can be obtained.

The application discloses a kind of S-delta-substituted caprolactam chemical / enzyme series preparation method, and the specific preparation method is: 1-substituted high allyl amine occurs dynamic kinetic resolution reaction with acrylic ester compound under the catalysis of alkaline protease (special treatment) and generates S-acryl (1-substituted high allyl) amine, then the product occurs intramolecular olefin metathesis under the catalysis of Grubbs reagent and finally generates S-delta-substituted caprolactam shown in formula (1), wherein, substituent R is phenyl, halogenated phenyl or C2-C12 alkyl.The application has mild reaction condition, is conducive to reducing the equipment requirement of preparation process, improves synthesis safety and economy;Secondly, the reaction course of the method is simple, and single configuration S-delta-substituted caprolactam can be obtained by one-pot reaction, with very high atom economy.

The invention belongs to the technical field of bioengineering, and particularly provides a stable liquid alkaline protease preparation which comprises liquid alkaline protease, NaCl, polysaccharide and histidine. Based on the mass of the liquid alkaline protease, the addition amount of NaCl is 5%-10%, the addition amount of polysaccharide is 0.1%-0.5%, and the addition amount of histidine is 0.02%-0.1%. According to the stable liquid alkaline protease preparation provided by the invention, NaCl, polysaccharide and histidine are added into alkaline protease, filtration and sterilization are performed after pH is adjusted, the stability of the liquid alkaline protease is obviously improved, heat preservation is performed for 6 months at the temperature of 45 DEG C, and the enzyme activity is basically free of loss. The preparation has simple components and is especially suitable for feed and food industries.

The application discloses a preparation method and application of Lactobacillus plantarum fermentum based on environmental stress, and comprises the following steps: activating Lactobacillus plantarum; inducing and culturing the Lactobacillus plantarum in a culture medium containing sodium dodecyl sulfate to obtain Lactobacillus plantarum under environmental stress; dissolving milk powder in deionized water, adding alkaline protease, adjusting the pH to 7-10, and performing enzymolysis to prepare an enzymolysis solution; mixing the enzymolysis solution with sugar to obtain a fermentation substrate; inoculating the Lactobacillus plantarum into the fermentation substrate, performing fermentation culture, centrifuging to collect supernatant, sterilizing, and obtaining the Lactobacillus plantarum fermentum under environmental stress. It is found for the first time that sodium dodecyl sulfate stress can promote the synthesis of anti-inflammatory peptides of Lactobacillus plantarum, and the efficacy threshold of a natural strain is broken. The method is mild in conditions, simple in operation, is conducive to industrialized production, and fully guarantees the stability of product quality.

The application discloses a method for preparing an oat-based beverage through biological enzymolysis and a product thereof, and comprises the following steps: continuously hydrolyzing starch, cellulose, protein and other substances in oat slurry by using high-temperature-resistant amylase, cellulase, saccharifying enzyme, papain and alkaline protease, sufficiently releasing reducing substances in the oat, simultaneously generating reducing peptides, improving the free radical scavenging capacity of the oat slurry, and improving the emulsification stability of the oat slurry due to the moderate degradation of macromolecular substances such as starch, cellulose and protein; glycerol is added in three stages at a controlled speed, so that the glycerol is fully mixed with flaxseed oil, and excessive glycerol is avoided from adhering to lipase to reduce the activity of the enzyme, thereby improving the reaction efficiency.

The invention relates to the technical field of gene engineering and protein modification, in particular to a high-temperature-resistant alkaline protease mutant. On the basis of wild type alkaline protease AprE from bacillus clausii, a mutant containing mutation sites selected from V30M / I, I77L / V, S101G, P127M, N138Q / K, F183K / D, V197I / L, P219F / E, A226S / T and N232D is provided, the heat resistance of the mutant is remarkably improved, and wide application of the mutant in the field of washing industry is promoted.

The present application relates to the field of eggshell membrane peptide, in order to solve the problem that the proportion of polypeptide with main function of anti-inflammatory effect is low in the eggshell membrane peptide product obtained by hydrolysis of existing eggshell membrane, provide an eggshell membrane peptide and a preparation method thereof, and an application of the eggshell membrane peptide in preparation of anti-inflammatory drugs, comprising: S100, after adding eggshell membrane powder into pure water, adjusting pH, then adding pepsin, enzymolysis for 2-5h, and the enzymolysis temperature is 35-38 DEG C, to obtain a first mixture; S200, the first mixture is subjected to enzyme inactivation process and ultrafiltration process to obtain a first hydrolysate and a first ultrafiltrate; S300, after adjusting the pH value of the first ultrafiltrate to 8-9, adding alkaline protease, enzymolysis for 6-10h, and the enzymolysis temperature is 36-38 DEG C, to obtain a second mixture; S400, the second mixture is subjected to ultrafiltration process to obtain a second ultrafiltrate and a second hydrolysate; S500, after drying the second hydrolysate, a first polypeptide composition is obtained. The present application explores the effect of different hydrolysate components on chondrocyte anti-inflammatory, and screens out eggshell membrane peptides with better effect.

The invention relates to the technical field of preparation of deep-sea longevity fish precise active peptides, in particular to a deep-sea longevity fish precise active peptide with uric acid reducing and anti-inflammatory effects as well as a preparation method and application of the deep-sea longevity fish precise active peptide. The preparation method comprises the following steps: carrying out medium-temperature pretreatment, carrying out step-by-step enzymolysis with alkaline protease and acid protease, centrifuging, filtering, carrying out ultrafiltration interception and the like, and screening out 10 non-reported non-toxic active peptide fragments. The active peptide has a multi-target synergistic effect, inhibits the activity of xanthine oxidase, regulates and controls the expression of uric acid resorption protein, regulates and controls the expression of uric acid transporter protein, realizes bidirectional regulation of uric acid metabolism, efficiently removes hydroxyl radicals, activates superoxide dismutase and reduces the content of inflammation-related factors. The technology is simple and easy to control, low in equipment requirement and suitable for large-scale production, the active ingredients are natural, safety is high, the active ingredients can serve as functional factors to be applied to functional food, health care products and the like, and safe and diversified intervention schemes are provided for hyperuricemia and related inflammation problems.

The application belongs to the technical field of food processing, and more particularly relates to a method for preparing a milk-like instant egg white beverage by using a composite enzyme preparation. The method comprises the following steps: adding a composite enzyme preparation into egg white liquid, performing enzymatic hydrolysis treatment, adding a sweetening agent, an acidity regulator and a stabilizer after enzyme inactivation, uniformly mixing, obtaining a mixed liquid, performing homogenization treatment and ultra-high temperature instant sterilization treatment on the mixed liquid, and obtaining a milk-like instant egg white beverage; wherein the composite enzyme preparation comprises at least three of alkaline protease, papain, flavor protease and trypsin. The method of the application simplifies the production process, reduces energy consumption, and makes the product have excellent texture characteristics by directional enzymolysis of a specific composite enzyme preparation. The egg white protein content in the obtained product is greater than 90%, the product has a milk-like appearance, a delicate and smooth taste, and can be stored at room temperature for more than 6 months without separation or whey separation. The method of the application is simple in process, low in cost, excellent in product quality, and suitable for industrial production.

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

The invention relates to the technical field of food processing, in particular to a method for enhancing the bean flavor of soybean milk and reducing the beany flavor through composite enzymolysis and bacterium fermentation. According to the method for enhancing the bean flavor of the soybean milk and reducing the beany flavor through the combination of the composite enzymolysis and the bacterium fermentation, the soybeans are firstly soaked, then the soaked soybeans are mixed with water, and the mixture is ground and cooked to obtain original soybean milk; adding porcine pancreas lipase into the original soybean milk to carry out enzymolysis, then adding alkaline protease to carry out enzymolysis, and then carrying out enzyme deactivation to obtain enzymolysis soybean milk; and performing sterilization treatment on the enzymolysis soybean milk, and then inoculating lactobacillus gasseri for fermentation treatment to obtain a fermented soybean milk finished product. According to the method disclosed by the invention, the beany flavor and the bean flavor of the soybean milk are taken as a comprehensive target, and the bean flavor can be effectively improved on the basis of removing the beany flavor through organic combination of enzyme treatment and microbial fermentation, so that a theoretical basis can be provided for accurate regulation and control of the flavor of the soybean milk, and a technical support can be provided for processing and production of high-quality soybean milk.

The invention relates to the field of yeast extracts, in particular to a yeast extract containing arginine as well as a preparation method and application of the yeast extract. Wherein the content of arginine in the yeast extract containing arginine is greater than or equal to 6%, and the preparation method comprises the following steps: step 1, culturing a strain to obtain yeast milk; 2, extracting the yeast milk obtained in the step 1, and performing solid-liquid separation to obtain supernate; step 3, performing enzymolysis on the supernate obtained in the step 2, and performing solid-liquid separation to obtain a yeast extract containing arginine; wherein in the step 3, the enzyme used for enzymolysis comprises one or more than two selected from a substance group consisting of papain, alkaline protease and neutral protease. By adopting the preparation method disclosed by the invention, the arginine in the yeast can be more effectively enriched and can be up to 7.35% at most, and the method can be widely applied to the fields of preparing flavor modifiers of foods or human nutrition supplements and the like.

The invention relates to the technical field of food-grade materials, in particular to a food-grade porous material and a preparation method thereof. The preparation method comprises the following steps: gradually carrying out enzymolysis on corn flour by alkaline protease and amylase under the conditions of proper temperature and pH, continuously stirring, adding food-grade vegetable gum, and forming porous glycoprotein under the assistance of ultrasonic waves; the porous glycoprotein is uniform in pore size and is 0.5-3 microns, and the surface of the porous glycoprotein is rich in functional groups, so that the porous glycoprotein has good adsorption performance and has very high adsorbability on hydrophobic compounds such as metal ions, pesticide residues, kitchen oil stains and the like. The preparation process is simple, chemical reagents do not need to be introduced, and safe and non-toxic substances are completely adopted as materials for preparing the porous material, so that the product is food-grade, small in damage to human bodies and the environment and wide in application in the food field.

This invention relates to the field of feed, specifically disclosing a method for preparing selenium- and strontium-enriched amino acid chelated feed; including the preparation of selenium / strontium-enriched amino acid fermentation products, the preparation steps of which are as follows: S1: Inoculating activated microalgae and yeast strains into a culture medium supplemented with selenium and strontium compounds, the pH of the culture medium is 6.5-7.5, the culture temperature is 25-35℃, and the culture is carried out under light and aeration conditions for 5-7 days; S2: Collecting selenium / strontium-enriched algal biomass using a flocculant, and ultrasonically treating the selenium / strontium-enriched algal biomass for 10-20 minutes, then adding soybean meal and rapeseed cake to the selenium / strontium-enriched algal biomass and stirring; S3: Adding cellulase, papain, alkaline protease, and pectinase for enzymatic hydrolysis to obtain selenium / strontium-enriched amino acid fermentation products. The selenium- and strontium-enriched amino acid chelated feed and its preparation method of this invention can improve the intestinal health of animals, increase the absorption and utilization rate of nutrients, and enhance animal immunity.

The present application relates to the technical field of genetic engineering and protein engineering, and particularly relates to a basic protease mutant with improved specific activity. The mutant comprises an amino acid sequence with at least 90% identity with SEQ ID NO: 1, and comprises substitution of amino acids at at least one position selected from the group consisting of 63, 109, 120, 154, 191, 261 and 328, compared with SEQ ID NO: 1. The specific activity of the mutant is generally increased by 13.12%-79.32% compared with wild type, which is beneficial to reduce the production cost of the enzyme and promote its wide application in the field of industrial enzymes.