2204 results about "Oligosaccharide" patented technology

The invention belongs to the field of agricultural chemistry and bio-fertilizer, and discloses a fertilizer synergist based on polyaspartic acid, alginate oligosaccharide and mannan oligosaccharide and a preparation method of the fertilizer synergist. According to the synergist, polyaspartic acid derived from plant source amino acid, alginate oligosaccharide extracted from natural brown algae and mannan oligosaccharide extracted from plants are used as main raw materials, and the polyaspartic acid, the alginate oligosaccharide and the mannan oligosaccharide cooperate to form an induction-complexation-adsorption three-effect-in-one mechanism, wherein the alginate oligosaccharide and the mannan oligosaccharide induce plant root activity and stress resistance gene expression; the polyaspartic acid is dominated to form a multi-point weak complex network, so that slow release and controlled release of nitrogen and potassium ions are realized; the three components cooperate on the surface of soil colloid to form an adsorption layer, and nutrient leaching loss is reduced. The preparation process adopts a green process of'enzymatic pretreatment-segmented complexing-low-temperature forming ', so that the oligosaccharide activity is maintained, and the use of an organic solvent is avoided. The obtained synergist can significantly improve the nitrogen utilization rate and the root activity and prolong the fertilizer efficiency period, and is suitable for green and efficient agricultural production of various crops.

According to the high-gel-quality minced fillet gel and the preparation method thereof, frozen minced silver carp is unfrozen and then subjected to ice-temperature vacuum dehydration and ultrahigh-pressure homogenization treatment, a myofibrillar protein molecular chain is promoted to stretch through mild shearing force, and a TG enzyme acting site is fully exposed; then chopping and mixing with table salt, starch, TG enzyme coated porous starch-curdlan / sodium alginate oligosaccharide nanosphere dispersion liquid and ice water at low temperature, shielding TG enzyme by nanospheres through a core-shell structure at low temperature so as to avoid advanced activation, and accurately releasing during heating so as to catalyze crosslinking; finally, step-by-step heating gelation is performed, so that the strength and uniformity of minced fillet gel are remarkably improved, the flavor is improved, and the method is suitable for industrial production.

The invention relates to the technical field of compound fertilizers, and discloses a boron-zinc-molybdenum synergistic compound fertilizer, which is prepared from the following raw materials in parts by weight: calcium nitrate, ammonium polyphosphate, potassium sulfate, magnesium sulfate, disodium octoborate tetrahydrate, sugar alcohol chelated zinc, sodium molybdate and a synergistic auxiliary agent, the feed additive is prepared from a feed additive, an activator, 5-alginic acid oligosaccharide, aminolevulinic acid, sugar alcohol chelated magnesium, an antagonist, a stress-resistant enhancer and a coating material. According to the boron-zinc-molybdenum synergistic interaction compound fertilizer and the preparation process thereof, the disodium octoborate tetrahydrate, the sugar alcohol chelated zinc and the sodium molybdate are compounded according to a specific proportion, antagonism is avoided through proportion limitation, the synergistic effect of the three elements is remarkably enhanced, and the problem that a single element is insufficient or excessive is solved; chelated elements such as sugar alcohol chelated zinc and sugar alcohol chelated magnesium are combined with an activating agent (humic acid chelated calcium and silica sol) to form a gel-state chelate, so that the trace elements can be prevented from being fixed by soil, and the transfer efficiency of the trace elements in crops is improved.

The invention relates to the technical field of fertilizers, in particular to an environment-friendly water-soluble fertilizer containing a seaweed extract and polyglutamic acid. The water-soluble fertilizer is prepared by preparing seaweed oligosaccharide and double-grafted poly-L-gamma-sodium glutamate and compounding and complexing the seaweed oligosaccharide and the double-grafted poly-L-gamma-sodium glutamate, has the characteristics of low salting-out, high stability, no precipitation, good slow release performance and the like, and can continuously release nutrients and keep a solution clear and transparent under a low-salt condition; and because the polyglutamic acid and seaweed extract compound drip irrigation agent has the chelation and water retention characteristics of the polyglutamic acid and the natural growth promoting effect of the seaweed extract, the crop rhizosphere nutrient absorption efficiency and stress resistance are remarkably improved, the compound drip irrigation agent is suitable for drip irrigation and water and fertilizer integrated application of greenhouse vegetables, fruit trees and field crops, and the comprehensive effects of high efficiency, low salt load and environment friendliness are achieved.

The present invention provides a fucosyltransferase polypeptide, which can be applied to the synthesis of human milk oligosaccharides (HMOs) and belongs to the field of enzyme engineering technology. The fucosyltransferase polypeptide described in the present application comprises a polypeptide having at least 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, and 100% identical amino acid sequence to the polypeptide shown in SEQ ID NO:1-25. The transferase polypeptide described in the present application improves the ability of the polypeptide shown in SEQ ID NO:1 to catalyze the synthesis of 2'-FL while also improving the specificity of the polypeptide catalyzing the substrate.

The application provides a Huangdache oligosaccharide with GLP-1 agonist activity and application thereof, and belongs to the technical field of medicines. 3 The oligosaccharide component ELYP-3 has a molecular weight of 3.2*10 3 Da, and the molar ratio of monosaccharides is rhamnose:galacturonic acid:glucose:galactose:arabinose = 1:32.42:45.37:9.11:6.54. The Huangdache oligosaccharide fragment obtained by glycosidase degradation has significant hypoglycemic and weight loss activities, the preparation process is simple, specific and green, and provides scientific basis and theoretical support for the development of natural GLP-1 agonists. Meanwhile, the functional oligosaccharide provides a wide application prospect for the development of medicines with blood glucose regulation.

The invention relates to the field of fermentation compounds, in particular to a compound for promoting GLP-1 secretion, a fermentation preparation method and application of the compound. According to the compound, fermented mulberry leaf powder is used as a main material, soybean oligosaccharide and rhizoma kaempferiae rhizome extract are used as synergistic materials, white birch juice concentrate and white kidney bean extract are used as auxiliary materials, the mulberry leaf powder is subjected to compound probiotic fermentation and multi-stage directional enzymolysis to enrich active components, and meanwhile, the soybean oligosaccharide is extracted and purified by adopting ultrasonic-assisted extraction in combination with a gradient alcohol precipitation method. Supercritical CO2 extraction is assisted to obtain a high-purity rhizoma kaempferiae rhizome active extract; finally, all the extracts are compounded in proportion and embedded through sodium alginate-chitosan wall material microcapsules, and the stability is improved with the assistance of a vitrification carrier and an antioxidant; the composition provided by the invention has a multi-target synergistic effect, and can significantly promote the secretion of GLP-1.

The invention relates to the technical field of synthetic biology, metabolic engineering and cell culture. The present invention provides a cell for the production of a negatively charged, preferably sialylated, oligosaccharide wherein the cell is genetically engineered to have or express, preferably overexpress, a hydrolytic UDP-N-acetyl-D-glucosamine-2-epimerase. The invention further provides the use of said cells in culture or incubation. Also described are methods of producing negatively charged, preferably sialylated oligosaccharides using the cells, and purification of the negatively charged, preferably sialylated oligosaccharides.

The invention relates to a particulate composition comprising, or substantially consisting of, urea, an inhibitor, preferably a urease inhibitor and / or a nitrification inhibitor, and an additive, wherein the additive comprises components (i), (ii), and optionally (iii): (i) one or more polyhydric alcohols; preferably one or more carbohydrates, preferably selected from monosaccharides, disaccharides, and oligosaccharides; (ii) a first polymer, preferably an amine-containing polymer; more preferably a polyvinylamine or a polyalkyleneimine; and (ii) optionally, a second polymer, preferably a polar polymer; more preferably a water-soluble polar polymer. The invention further relates to a process for producing the particulate composition, an additive for a particulate composition, and the use of the particulate composition as a fertilizer.

The invention discloses a multi-element soil fertility improvement biological modifier and a preparation method thereof, and belongs to the technical field of soil fertility improvement. The modifier is prepared from modified straw aerogel, a strontium titanate loaded lignin compound, lanthanide modified potassium feldspar powder, alginic acid oligosaccharide composite gamma-aminobutyric acid, carbon nitride quantum dots, bacterial cellulose nanofibers and polyaniline nanotubes according to the mass ratio of (18-22): (15-17): (13-15): (7-10): (10-13): (3-5): (7-10): (10-13): (5-8). The composite microbial inoculant is composed of a nano zero-valent iron-montmorillonite compound and a nitrogen fixation-phosphate solubilizing composite microbial inoculant. The modified straw aerogel and the bacterial cellulose nanofibers are interwoven to form a three-dimensional network framework, a habitat is provided for soil microorganisms, the water and fertilizer retention capacity of soil is enhanced, and meanwhile, the network structure promotes transmission of nutrients and water in the soil and improves the nutrient utilization efficiency.

The invention discloses a special growth regulator for pepper based on compounding of propionyl brassinolide and amino-oligosaccharin and application of the special growth regulator, and belongs to the technical field of agricultural biology. According to the regulating agent, 0.0008 to 0.0012 percent of propionyl brassinolide and 2.95 to 3.05 percent of amino-oligosaccharin are accurately matched with each other. The formula breaks through the contradiction between the root promotion requirement of high-dose amino-oligosaccharin and the safety threshold of low-dose brassinolide, and overcomes the phytotoxicity risk of the traditional dosage form. The regulator prepared by the invention can enhance the growth vigor of the pepper, improve the product and quality of the pepper, and also can effectively prevent viral diseases of the pepper.

The invention discloses a nutritional composition for promoting neurodevelopment and application, and provides a nutritional composition for promoting neurodevelopment, which comprises the following necessary components: a sialylated substance component comprising one or more of N-acetylneuraminic acid, sialylated oligosaccharide, sialylated protein and sialylated lipid; the whey protein component comprises alpha-lactalbumin; and a peptide component from casein, including a hydrolysate of casein; the nutritional composition comprises a sialylated substance component, a whey protein component and a casein-derived peptide component, and the mass ratio of the sialylated substance component, the whey protein component and the casein-derived peptide component in the nutritional composition is (0.5-10): (300-1): (100-0.5). The nutritional composition provided by the invention can promote brain development and cognitive functions, and can significantly promote neurodevelopment by scientifically matching the sialylated substance component, the whey protein component and the peptide component from casein.

The embodiment of the invention discloses a Yarrowia guilliermondii as well as a separation and screening method, an identification method and application of the Yarrowia guilliermondii. The preservation number of the Yarrowia guilliermondii is CGMCC (China General Microbiological Culture Collection Center) No.27603, and the preservation number of the Yarrowia guilliermondii is CGMCC No.27603. The Yarrowia guilliermondii disclosed by the embodiment of the invention has a very good prevention and control effect on postharvest diseases of fruits, and the prevention and control effect of the Yarrowia guilliermondii on the diseases can be enhanced by respectively adding auxiliary factors, namely calcium chloride, alginate oligosaccharide (AOS), phytic acid (PA) and metschhia yeast. Through identification, the antagonistic bacterium is a Yeyrozyma guilliermondii, and the antagonistic bacterium is a Yeyrozyma guilliermondii. The M.guilliermonii has a good control effect on gray mold, penicilliosis, black spot and aspergillus niger of strawberry, apple, pear and tomato fruits, can be rapidly colonized on fruit wounds, and can enhance the resistance-related enzyme activity of the fruits, occupy the wound space and induce the fruit resistance to reduce the morbidity of diseases.

The present application relates to a kind of Bifidobacterium longum infantis subsp.Imu-01 and its application. Specifically, the present application provides Bifidobacterium longum infantis subsp.Imu-01, culture, preparation and preparation of immune function improving product application. The present application provides that Bifidobacterium longum infantis can regulate the immune level of the subject, improve the content of intestinal butyric acid, improve the utilization of human milk oligosaccharide.

The invention relates to a series of fucosyl transferase polypeptides which can be applied to synthesis of human milk oligosaccharides (HMOs), and belongs to the technical field of enzyme engineering and genetic engineering. The invention provides an alpha-1, 3-fucosyltransferase polypeptide, which comprises a polypeptide with an amino acid sequence which is at least 70%, 75%, 80%, 85%, 90%, 95%, 99% and 100% identical to that of a polypeptide shown in SEQ ID NO: 1. Or a polypeptide having at least 70%, 75%, 80%, 85%, 90%, 95%, 99%, 100% of the same amino acid sequence as the polypeptide M1-21. The invention provides a polypeptide as shown in SEQ ID NO: 1 and M1-M21 polypeptides. The 3-FL catalytic synthesis capability of the polypeptide as shown in SEQ ID NO: 1 is improved; and the specificity of a catalytic substrate is improved.

The invention belongs to the technical field of preparation of food additives, and particularly relates to a method for extracting sa-hao seed gum and oligosaccharide thereof by using a compound enzyme method. According to the method provided by the invention, complete artemisia desertorum seeds are taken as a raw material, enzymolysis is carried out by using a compound system consisting of xylanase, cellulase and pectinase, and after enzyme deactivation and alcohol precipitation, the artemisia desertorum gum or the artemisia desertorum gum oligosaccharide can be obtained. Compared with a traditional water extraction method and an acid-base extraction method, the extraction yield is remarkably increased through the enzymolysis synergistic effect, the process is green and safe, no chemical residue exists, the molecular weight of the product is controllable, and high purity and functional activity are both achieved. The method is easy and convenient to operate, low in cost and suitable for large-scale production, and has wide application prospects in the fields of food, medicine and functional oligosaccharide development.

The invention discloses a bran fermented biological feed and a preparation method thereof, and belongs to the technical field of feeds. The bran fermented biological feed is prepared by uniformly mixing and fermenting the following raw materials: wheat bran, corn flour, soybean meal, calcium hydrogen phosphate, sodium chloride, an enzyme preparation, a water retention setting agent, a mildew preventive and water, wherein the enzyme preparation is prepared from lactobacillus plantarum, bacillus subtilis and saccharomycetes; the mildew preventive is prepared by the following steps: reacting chitosan oligosaccharide with propiolic acid to obtain modified chitosan oligosaccharide, reacting L-cystine with ethyl azidoacetate to obtain an azide compound, and finally reacting the modified chitosan oligosaccharide with the azide compound. The prepared bran fermented biological feed has an excellent mildew-proof effect and a low pulverization rate, and storage and transportation of the feed are facilitated.

The invention relates to pichia pastoris engineering bacteria and a preparation method thereof, and a method for producing cellooligosaccharide / disaccharide by using corn straws or wheat straws, and belongs to the technical field of genetic engineering. A cellulose incision enzyme gene and a cellulose excision enzyme gene are transferred into pichia pastoris engineering bacteria. The preparation method comprises the following steps: respectively inserting a cellulose incision enzyme gene and a cellulose excision enzyme gene into plasmids to construct expression vectors; transferring the expression vector into a competent cell of pichia pastoris GS115; and screening and identifying to obtain successfully transformed pichia pastoris engineering bacteria. According to the present invention, the pichia pastoris heterologous expression cellulose incision enzyme and cellulose excision enzyme are adopted to construct the pichia pastoris engineering strain capable of degrading the plant straw into the cellooligosaccharide / disaccharide, such that the reliable chassis strain is provided for the production of the starch from the cellulose;

The invention discloses a production method of fucosylated oligosaccharide. The core of the method is as follows: the GDP-D-rhamnose is converted into the GDP-L-fucose by using the GDP-D-rhamnose-3, 5-epimerase; the GDP-D-rhamnose is obtained by converting the GDP-D-mannose-4, 6-dehydratase and the GDP-4-keto-6-deoxy D-mannose reductase by taking the GDP-D-mannose as a substrate, and the GDP-D-rhamnose is obtained by taking the GDP-D-mannose as a substrate. The invention relates to a method for producing a fucosylated oligosaccharide, which is characterized in that a GDP-D-mannose-4, 6-dehydratase, a GDP-4-keto-6-deoxyD-mannose reductase, a GDP-D-rhamnose-3, 5-epimerase and a fucosyltransferase are expressed in a genetically modified host cell, and the fucosylated oligosaccharide can be produced by the way mentioned above.

The invention relates to the technical field of feed processing, and discloses a lactating sow feed containing fermentation raw materials and a preparation method of the lactating sow feed. A three-layer microcapsule coating auxiliary material is prepared by taking a vitamin premix, an amino acid compound, a compound enzyme preparation and a probiotic agent as core materials through three-layer coating; the basic raw materials comprise corn, wheat, bran, a fermentation raw material, a mineral premix and grease, auxiliary material coating and basic raw material treatment are carried out in parallel in double lines during preparation, and finally, mixing granulation is carried out; the grafted copolymer formed by the amidation reaction of the sodium carboxymethyl cellulose and the chitosan oligosaccharide can cooperate with the sodium alginate to prevent the damage under acidic conditions, and the survival rate of viable bacteria is kept at 85-87% after treatment is carried out for 2 hours under the acidic condition with the pH value of 2.0-3.0; compared with a traditional fermentation raw material coating scheme, the dosage of coating raw materials is reduced by 70% or above; meanwhile, the vitamin premix and the amino acid compound in the auxiliary material can reduce the diarrhea rate by 6% and increase the lactation yield of the sow by 7-18%.

The invention relates to the technical field of nutritional health-care food, and particularly discloses functional oral liquid capable of tonifying qi and blood and enhancing immunity based on ganoderma lucidum active ingredients and a preparation method. The composition comprises a ganoderma lucidum fermentation stock solution, ginseng, lucid ganoderma, astragalus membranaceus, angelica sinensis, fructus lycii, fructus hippophae, rhizoma polygonati, oyster nano peptide, raspberry and a chitosan oligosaccharide-vitamin E stabilizer. The preparation method comprises the following steps: crushing medicinal materials, performing graded extraction, performing ultrasonic integration with a ganoderma lucidum fermentation stock solution, performing membrane separation and purification, performing gradient vacuum concentration, adding a stabilizer under the protection of nitrogen, stirring, and finally performing nitrogen filling and pasteurization. The composition disclosed by the invention can be used for tonifying qi and blood and regulating immunity, the bioavailability is improved by virtue of synergy of ganoderma lucidum polysaccharide, ganoderma lucidum triterpenes and ginsenoside and an oyster nano peptide-sea buckthorn flavone composite carrier, and efficient retention and synergistic interaction of active ingredients are realized; in addition, low-temperature gradient concentration and mild sterilization are adopted in the preparation method, so that the heating time is shortened, and the quality stability of the product is ensured.

The invention belongs to the field of biological medicines, and particularly relates to a preparation method of a pomegranate peel extract. The method comprises the following steps: pretreating fresh pomegranate rind, and extracting with mixed alcohol solvents with different concentrations. According to the extraction method provided by the invention, the pomegranate rind can be fully swelled after being soaked in the alginate oligosaccharide aqueous solution, and active ingredients in the pomegranate rind can be fully extracted after subsequent treatment, so that the extraction efficiency is improved, and the solubility and the stability of the active ingredients are improved; according to the preparation method, the mixed alcohol solvent is added in a stepped manner, so that the extraction rate of active ingredients is increased, and meanwhile, the prepared extract is increased in removal rate of DPPH free radicals and has excellent oxidation resistance.

The invention belongs to the technical field of preparation of probiotics, and provides a bacterial strain with anti-allergic and immunity-improving effects and application of the bacterial strain. According to the method, a three-layer physical self-assembly structure is adopted, and polysaccharide-polyphenol layer-by-layer self-assembly coating treatment, lipid insertion layer treatment and calcium ion crosslinking protection coating treatment are sequentially carried out. And mannan oligosaccharide MOS and / or galactooligosaccharide GOS are / is mixed in the chitosan layer in a ratio of 0.05-0.15% w / v, and the surface sugar ligand density reaches 4-8 [mu] g per 10 CFU. The coating is constructed under the condition that the pH value is 5.4-5.8; the thickness of the lipid layer is 20-80 nm when the pH value is 5.6-6.2; the cross-linked layer is treated at the pH of 6.0-6.5, so that the gastric acid environment is stable for 2 hours, and the gastric acid is controllably released in intestinal juice for 2-4 hours. The prepared strain has the total thickness of 220-900 nm, the outermost layer coverage rate is larger than or equal to 85%, the gastric juice survival rate is remarkably improved, the strain can be prepared into an oral preparation to be used for preventing and relieving allergic diseases, the viable count of each dose is 1 * 10 <-1 > * 10 <-1 > CFU, and the process is mild and suitable for industrial production.

The invention discloses a preservative sprayed before picking of peach fruits and a spraying method thereof, and is characterized in that the preservative is prepared from the following raw materials in percentage by mass: 2-8% of alginate oligosaccharide, 0.05-0.2% of gamma-aminobutyric acid, 0.5-2% of capric triglyceride, 0.1-0.3% of glycerol, 1-3% of tween-80, 0.2-1% of sodium carboxymethyl cellulose and the balance of water. The method for spraying the preservative to the peach fruits before picking the peach fruits comprises the following steps: selecting peach trees with consistent tree age and growth vigor, starting from the 90th-110th day after the peach fruits bloom, spraying the peach fruits three times every three days, uniformly spraying the surfaces of the peach fruits until the surfaces of the peach fruits are in a dripping state, and spraying the preservative to the surfaces of the peach fruits. The method has the advantages that the commodity fruit rate of the picked peach fruits is increased, the storage period of the peach fruits is prolonged, the normal-temperature storage rotting rate of the peach fruits is reduced, the cold damage caused by low-temperature storage is relieved, and the quality and taste of the fruits are kept.

Disclosed is a method of treating liver ischemia reperfusion (I / R) injury in a subject. In some aspects, the method comprises providing a subject suffering from liver I / R injury or at risk of suffering liver I / R injury; and administering to the subject one or more heparan sulfate (HS) compounds. In some aspects, the one or more HS compounds comprises about 5 to about 18 saccharide units, optionally about 12 to about 18 saccharide units. In some aspects, the one or more HS compounds comprises about 12 saccharide units.

The invention discloses an amino acid water-soluble fertilizer and a production process thereof, and relates to the technical field of water-soluble fertilizers. Free amino acid is used as an organic nitrogen source, and the medium element calcium is combined, so that the crop quality is improved. The formula is low in cost, high in absorptivity, suitable for crop growth, simple and convenient to use and high in cost performance, and promotes the synergistic effect of nutrient elements. The method takes amino acid and calcium as raw materials, and has the characteristics of wide applicability, high output-input ratio and easiness in market promotion. The product is completely water-soluble, environment-friendly and safe, can regulate the physiological function of crops, increase the yield and amino acid content and improve the quality, and has remarkable economic benefits. In addition, activated ricinoleic acid carboxyl is combined with fucoidan enzymatic hydrolysis oligosaccharide to construct the microcapsule, so that efficient utilization of resources is realized.

The present invention belongs to the field of enzyme engineering and food engineering technology, and specifically relates to the directed evolution and site-directed mutagenesis of a lactase enzyme molecule and its application in fresh milk. The amino acid sequence of the lactase mutant obtained by the present invention is shown in SEQ ID NO.4. Through the directed artificial evolution of the lactase molecule, a new lactase molecule is obtained that can efficiently convert lactose in fresh milk and synthesize oligosaccharides at a relatively low temperature, and is rapidly inactivated at a subsequent elevated temperature (such as pasteurization). This facilitates the highly nutritious in situ bioconversion of lactose in fresh milk into prebiotic oligosaccharides, further improving the nutritional value of fresh milk and expanding the fresh milk consumer group.

This disclosure is in the technical field of synthetic biology and metabolic engineering. More particularly, this disclosure is in the technical field of cultivation or fermentation of metabolically engineered cells. This disclosure describes a cell metabolically engineered for production of a mixture of at least three different oligosaccharides. Furthermore, this disclosure provides a method for the production of a mixture of at least three different oligosaccharides by a cell as well as the purification of at least one of the oligosaccharides from the cultivation.

The invention provides a biological organic fertilizer and a preparation method thereof. The biological organic fertilizer is prepared from the following raw materials in parts by weight: 10 to 15 parts of rice husk, 8 to 12 parts of peanut shell, 10 to 15 parts of bagasse, 15 to 20 parts of straw, 20 to 25 parts of livestock manure, 5 to 10 parts of pond sludge, 3 to 5 parts of plant ash, 5 to 10 parts of oil meal, 5 to 10 parts of ammonium phosphate, 2 to 5 parts of low-temperature complex microbial inoculants, 3 to 6 parts of seaweed oligosaccharide, 5 to 10 parts of modified vermiculite powder and 10 to 20 parts of photothermal conversion microspheres. According to the invention, waste is taken as a basic raw material and is matched with ammonium phosphate to rapidly supplement available nutrients, and meanwhile, the low-temperature complex microbial inoculant, the modified vermiculite powder and the photothermal conversion microspheres are introduced to form a synergistic interaction system. Vermiculite powder is modified, so that the nutrient adsorption and slow release capability is improved, a carbon source and low-temperature protection are provided for microorganisms, and the cell membrane stability is enhanced. The photothermal conversion microspheres efficiently absorb sunlight and convert the sunlight into heat energy, a local and mild heat island effect is formed around the fungicide, the microenvironment temperature is increased, breeding of the fungicide is remarkably accelerated, and therefore organic matter decomposition and nitrogen conversion are accelerated.

The invention discloses a chitosanase mutant which is derived from bacillus subtilis and has the capacity of hydrolyzing chitosan to produce chitosan disaccharide per unit and belongs to a GH46 family, and application of the chitosanase mutant in hydrolyzing chitosan to produce chitosan oligosaccharide. Compared with wild type chitosanase capable of producing chitodisaccharide and chitotriose, the chitosanase mutant has the advantage that the chitodisaccharide can be produced per unit when the chitodisaccharide is hydrolyzed by the chitosanase mutant. The invention provides eight kinds of chitosanase mutants, and the mutants are obtained by carrying out site-specific mutagenesis on 21st-site glycine on the basis of wild type chitosanase and respectively mutating the 21st-site glycine into lysine, arginine, leucine, histidine, methionine, tyrosine, proline and glutamine. The mutant can hydrolyze chitosan under mild conditions to produce chitosan oligosaccharide with single polymerization degree, and can greatly relieve the difficulty in separation and purification in chitosan oligosaccharide production.