253 results about "Chitin" patented technology

The invention relates to an instant composition with a long-acting oral health-care function for dogs and cats as well as a preparation method and application of the instant composition, and belongs to the technical field of pet food and pet oral care. The composition comprises 20%-30% of whey protein powder, 10%-20% of hydrolyzed gelatin, 1%-3% of low-molecular-weight chitin saccharide gum, 1%-2% of modified cassava starch, 2%-5% of sodium alginate, 1%-3% of fructo-oligosaccharide, 0.03%-0.08% of lysozyme, 0.03%-0.08% of tea polyphenol, 0.05%-0.15% of zinc gluconate, 0.05%-0.1% of persimmon tannin, 3%-5% of tuna hydrolysate, 4%-6% of whole goat milk powder, 2%-4% of skim yoghurt powder and the balance water. The added active ingredients have long-acting slow-release and continuous effects in the formula, oral pathogenic bacteria can be effectively inhibited, dental plaque and dental calculus formation can be reduced, halitosis can be lastingly relieved, and the toothpaste has good market competitiveness.

The invention discloses a chitin-silicon-calcium-based modified material for rammed earth wall repair and a weather resistance evaluation method thereof, and belongs to the technical field of rammed earth wall repair, the chitin-silicon-calcium-based modified material comprises metakaolin, calcium oxide, quartz and chitin; the ratio of chitin to metakaolin to calcium oxide to quartz is 1: 1: 2: 4; the method comprises the following steps: pre-treating at the earlier stage of a test, evaluating freeze-thaw cycle performance, evaluating dry-wet cycle performance, evaluating salt corrosion resistance, analyzing association between a microstructure and a strength performance, and finally, revealing a material degradation rule and mechanism by combining scanning electron microscope observation, unconfined compressive strength test and crack rate analysis. When the freezing and thawing cycle number N is less than or equal to 5, the dry and wet cycle number I is less than or equal to 9, and the salt solution concentration c is less than or equal to 0.3 mol / L, the characteristics of freezing and thawing resistance, dry and wet resistance, salt erosion resistance and the like of the modified material are obviously improved; after the modified material is added, internal pores of plain soil can be filled, unconfined compressive strength of a soil body is enhanced, and long-term durability of the soil body is improved.

To provide a high-concentration dispersion of nanosized chitin having a uniform and fine fiber width.SOLUTION: A dispersion of nanosized chitin contains nanosized chitin with a fiber width of 20 nm or less in a concentration of 10 wt.%-30 wt.%.SELECTED DRAWING: Figure 1

The invention discloses allyl functionalized hyaluronic acid hydrogel as well as a preparation method and application thereof in electrolyte, and belongs to the technical field of hydrogel electrolyte. And dissolving the modified hyaluronic acid in a solvent, sequentially adding a cross-linking agent, the modified chitin nanofibers and an initiator, carrying out polymerization reaction at a preset temperature for a preset time to obtain hydrogel, and soaking the hydrogel in an electrolyte to obtain the modified hyaluronic acid hydrogel electrolyte. According to the scheme, the existing problems that a traditional hydrogel electrolyte is prone to icing at low temperature, the ionic conductivity is suddenly reduced, and the mechanical performance is degraded are solved, and the mechanical strength is enhanced by constructing an allyl functionalized hyaluronic acid three-dimensional chemical cross-linked network; modified chitin nanofibers are introduced to bind water molecules through hydrogen bonds to inhibit growth of ice crystals, graphene quantum dots are added to optimize an ion transmission path, and the hydrogel electrolyte which still keeps high ionic conductivity, excellent freezing resistance and high mechanical strength at the low temperature of-40 DEG C is prepared.

The invention provides a nutrient solution formula. The nutrient solution formula comprises organic nitrogen, organic phosphorus, organic potassium, active calcium, quick-acting sulfur, magnesium, zinc, selenium, ferrous sulfate, organic silicon, expanded fertilizer, mineral source humic acid, chitin, live bacterial fertilizer, boric acid, manganese sulfate, zinc sulfate heptahydrate, ammonium molybdate, copper sulfate heptahydrate, disodium iron ethylenediaminetetraacetate, citric acid and water. According to the nutrient solution formula and the preparation system thereof provided by the invention, microelements are added into the formula, so that the nutrient requirements of vegetables during growth are met, the growth of the vegetables is promoted, and meanwhile, citric acid is added, so that the nutrient solution is stable in property, and the effectiveness of the nutrient solution can be kept in a relatively long period; the physiological acid-base reaction caused in the nutrient solution absorption process of the leaf vegetables can be kept stable, the activity of the root system is improved through high water-soluble phosphorus in the formula, the photosynthesis is improved through the magnesium element, long-acting biological sulfur is provided, and continuous energy supply is provided.

The invention provides a method for preparing high-activity chitosan oligosaccharide based on a microbial fermentation method. The method comprises the following steps: cooling a fermentation culture medium containing chitin powder, inoculating an aspergillus niger seed solution under stirring and ventilation, and fermenting for 24 hours; stopping stirring for 30 seconds, adding a soybean protein isolate solution, reducing the rotating speed to 180 rpm, and fermenting for 12 hours; continuously reducing the rotating speed to 150 rpm, adding a soybean protein isolate solution, and fermenting for 12-14 hours; and centrifuging the fermentation liquor, taking supernate, filtering, adding a xanthan gum solution, stirring, concentrating, drying in vacuum, and crushing, thereby obtaining the product. According to the method disclosed by the invention, the industrial pain points that oligosaccharide is easy to degrade and active sites are easy to oxidize in traditional fermentation are solved by virtue of segmented dynamic electrostatic combination and deep synergy of aspergillus niger directional fermentation enzyme production and soybean protein isolate, and the preparation of the high-activity chitosan oligosaccharide is realized.

This invention discloses a chitinase-producing Bacillus albus A01 and its application in the fermentation of shrimp and crab solid waste. The chitinase-producing Bacillus albus is named... Bacillus albus A01, with accession number CCTCC: M 20252571; the 16S rDNA gene sequence of this chitinase-producing Bacillus albus strain A01 is shown in SEQ ID NO.1. The fermentation agent of this strain can effectively degrade the chitin content in shrimp and crab solid waste, and improve the nutritional value of shrimp and crab fermented powder through solid-state fermentation. This invention solves the problem of unsatisfactory fermentation effects of existing feed fermentation strains, and has great application potential for improving the feed nutritional quality of shrimp and crab fermented powder and developing feed resources.

The application discloses a coffee husk polysaccharide-rubber latex serum composite bio-organic water-soluble fertilizer and a preparation method thereof, and relates to the technical field of organic fertilizer. The coffee husk polysaccharide-rubber latex serum composite bio-organic water-soluble fertilizer comprises the following raw materials in parts by weight: coffee husk polysaccharide extract 20-25 parts, rubber latex serum 15-20 parts, water-soluble nano sulfur powder 3-6 parts, nano attapulgite colloidal 4-7 parts, potassium humate 2-5 parts, microcapsule fungicide 4-6 parts, amino acid chelated nutrient solution 18-22 parts, functional additive 3-5 parts and deionized water 30-40 parts. The coffee husk polysaccharide-rubber latex serum composite bio-organic water-soluble fertilizer prepared by the application has good heavy metal synergistic passivation capacity and low water-insoluble content, and has a significant yield-increasing effect on Chinese cabbage.

The invention discloses a high-strength nano-composite antibacterial fabric which comprises a base fabric and a modified and sol-gel nano layer, the modified and sol-gel nano layer and the base fabric are compounded and smeared to form the nano-composite antibacterial fabric, and the modified and sol-gel nano layer is coated with the modified and sol-gel nano layer to form the high-strength nano-composite antibacterial fabric. The modified sol-gel nano layer comprises titanium dioxide sol, nano zinc oxide and a silver antibacterial agent, the base layer fabric is prepared from the following raw materials in percentage by weight: 10% of chitin fiber, 50% of Coolplus fiber, 40% of cotton fiber and 16.7 tex of yarn linear density, and the base layer fabric is prepared from the following raw materials in percentage by weight: 10% of chitosan fiber, 50% of Coolplus fiber, 40% of cotton fiber and 16.7 tex of yarn linear density. Compared with the prior art, the fabric has the advantages that a layer of uniform and firm porous nano antibacterial film is formed on the surface of the fabric, so that staphylococcus aureus and pathogenic escherichia coli can be effectively killed; the double-layer fabric formed by combining the chitin fibers, the Coolplus fibers and the cotton fibers has good antibacterial, bacteriostatic, rapid moisture absorption and moisture conduction functions.

The utility model discloses green high-quality chitin treatment equipment, which relates to the technical field of biological catalytic processing, and comprises a bottom plate and a ball mill, the ball mill is arranged above the bottom plate, a plurality of sieve pores are arranged on the outer wall of the ball mill, and the sieve pores are communicated with the bottom plate. A first vertical plate and a second vertical plate are fixedly arranged on the upper surface of the bottom plate and located on the two sides of the ball mill correspondingly, one end of the ball mill is rotationally connected with the second vertical plate, a feeding shell is fixedly arranged at the position, corresponding to the ball mill, of the inner side of the first vertical plate, and the end, close to the feeding shell, of the ball mill is open. One end of the ball mill is rotationally connected with the feeding shell, a feeding hopper is arranged on the upper side of the feeding shell in a communicating mode, an acid leaching pool is arranged on the upper surface of the bottom plate and located below the ball mill, and a rotating rod is rotationally arranged between the first vertical plate and the second vertical plate and located below the ball mill. The device disclosed by the utility model has the characteristics of small environmental pollution, uniform and stable product and high enzyme instantaneity.

The invention relates to a method for directly preparing chitin nanofibers from shrimp and crab shells based on a deep eutectic solvent system and the chitin nanofibers. The invention discloses a method for directly preparing chitin nanofibers from shrimp and crab shells based on a deep-eutectic solvent system. The method comprises the following steps: mixing a hydrogen bond donor and a hydrogen bond acceptor to obtain the deep-eutectic solvent system; the shrimp and crab shell powder and the deep eutectic solvent system react for 2-6 h at the temperature of 40-100 DEG C, and the stirring speed is 200-500 r / min; carrying out ultrasonic treatment for the first time under the conditions that the power is 800 to 2400W, the frequency is 20 to 25kHz and the total ultrasonic time is 30 to 180 minutes; and after the reaction is finished, separating, washing and carrying out secondary ultrasonic treatment to obtain the chitin nanofiber. The three processes of deproteinization, demineralization and chitin nanocrystallization can be synchronously realized in the same reaction system, the technological process is simplified, the energy consumption and the environmental pollution are reduced, and the yield and the quality of the chitin nanofiber are improved.

An exemplary embodiment of the present disclosure provides a membrane including a supporting base layer, which can be permeable, and a dual layer oxygen barrier film disposable over the supporting base layer. The supporting barrier film can include a polymeric or paper-based material. The dual layer oxygen barrier film can include a chitin material and a cellulosic material. The cellulosic material of the dual layer oxygen barrier film can be the same material as the permeable membrane or can be any other cellulosic material.

The present application relates to a kind of carbonized iron and nitrogen coordination iron co-doped nitrogen and graphene carbon material and preparation method and application, with six hydrated ferric chloride as iron source, with chitin as nitrogen, carbon source. By simple one-step method, after mixing, calcination, grinding way, carbonized iron and nitrogen coordination iron co-doped nitrogen and graphene carbon material is synthesized.The material prepared by the present application presents two-dimensional layered structure, after adding potassium hydrogen peroxodisulfate oxidant, the material can completely remove the active pharmaceutical ingredient naphthyl in water in a short time.Naproxen.The synthesis method proposed in the present application is simple and easy to operate, and the material performance is excellent, which can provide a new design idea for nitrogen coordination iron nanomaterial supported by carbon material, and be applied to the remediation of contaminated water.

The present application provides a kind of ship hull barnacle protection net.The support layer of the protection net is nanofiber membrane with micron pit array formed by laser etching, the inside is attached to the adhesive made of modified dopamine-acrylate copolymer, nano-silica, calcium alginate microspheres, chitosan, chitin nanofiber, lanolin and antioxidant, and the outside is compounded with stainless steel wire mesh.The present application realizes long-term inhibition of barnacles through the physical barrier of the hydrophobic support layer and the synergistic effect of the antifouling components in the adhesive without adding toxic antifouling agents, and has the characteristics of firm bonding, excellent mechanical properties, environmental protection and non-toxicity, effectively solves the problems of poor antifouling effect, insufficient bonding reliability and poor environmental protection of existing protection materials, and is suitable for barnacle protection of underwater parts of ship hull.

The application relates to a crisp type pre-conditioned food of tussah pupae and a preparation method thereof. The method is characterized in that fresh tussah pupae are used as raw materials, a series of processing technologies such as spraying and moisturizing of organic acid, temperature control, inorganic acid immersion and killing, microbial-enzymatic treatment of tussah pupae, pickling and baking are combined to prepare the crisp type pre-conditioned food of tussah pupae, the method is simple in operation, can change the permeability of the chitin shell of the tussah pupae, increase the migration rate of the seasoning, reduce the proportion of the burst plasma, and simultaneously reduce the oil oxidation caused by repeated baking treatment.

This invention belongs to the field of edible fungus harvesting control, and particularly relates to an edible fungus detection system based on short-wave infrared multi-band fusion. The system includes an acquisition module, a detection module, and a response module. The acquisition module simultaneously acquires images of edible fungi, infrared multi-band data, and environmental sensor data. The detection module processes the data using a multimodal recognition model, extracting key indicators such as chitin content, moisture content, mold metabolites, and surface texture through parallel feature extraction, and then integrates and outputs mold probability, maturity level, and adaptive capture parameters. The response module executes early warning or precise capture based on these parameters. This invention, through multimodal fusion and anti-interference design, achieves non-destructive, rapid, and accurate detection of the internal quality of edible fungi, improving the level of harvesting automation.

A method of foam production is described. The method includes providing a foam precursor including one or more components, the one or more components including at least one of chitin, chitosan, or chitosan oligosaccharide and a solvent. The method further comprises exposing the foam precursor to radiation. The radiation is of a wavelength to heat the foam precursor. A system for foam produced is described, the system including a mixer configured to output a foam precursor including one or more components. The one or more components include at least one of chitin, chitosan, or chitosan oligosaccharide. The system further includes a radiation emitting system positioned to receive the foam precursor from the mixer and expose the foam precursor to radiation to heat the foam precursor to form a solid foam.

This invention provides a method for preparing carboxylated chitin with extremely low deacetylation degree, relating to the field of biomaterials technology. By employing a more reactive bromoacid as the carboxylating agent and optimizing the pretreatment method and reaction parameters (molar ratio, temperature, and time), the nucleophilic substitution reaction rate is significantly accelerated, enabling the initial reaction phase to be completed rapidly within a very short reaction time. The increased reaction rate effectively shortens the time the chitin molecular chain is exposed to an alkaline environment, thereby greatly suppressing the accompanying deacetylation side reaction, ultimately achieving an extremely low degree of deacetylation while maintaining a high degree of substitution. The extremely low DD value indicates that the product retains a large number of natural acetamide groups, which helps reduce the cytotoxicity of the material and improves its hydrophobic interactions, laying the foundation for subsequent regulation of material properties (such as viscoelasticity).

The invention discloses a ten-thousand-mu ecological cycle agricultural industrial park system based on shrimp shell fermentation and fly maggot culture, fresh shrimp shells are used as raw materials and are subjected to probiotic fermentation to serve as a fly maggot culture medium, and large-scale fly maggot culture is realized by combining a fly workshop and a fly maggot greenhouse; the method comprises the following steps: deeply processing and extracting antibacterial peptide, chitin, protein powder and fly maggot oil in fly maggots, and preparing an antibiotic-free active probiotic fresh material from fly maggot residues, culture medium residues, traditional Chinese medicine residues and rumex hanus extraction by-products; feeding ducks and fishes with fresh feed; the duck manure is subjected to biogas treatment and solid-liquid separation to serve as organic planting base fertilizer and nutrient solution, and biogas power generation is supplied to industrial parks; the radix astragali and the rumex hanus are synchronously and organically planted, the radix astragali and the rumex hanus are deeply processed, and a by-product feedback fly maggot culture medium and antibiotic-free feed are prepared. According to the method, a shrimp shell-fly maggot-livestock and poultry breeding-biogas engineering-organic planting full-closed-loop ecological cycle system is constructed, zero waste of resources and industrial scale are achieved, fish meal and broad-spectrum antibiotics are replaced with products, and the market application space is wide.

The present invention relates to a method for treating a chitin-containing material comprising: (i) milling the chitin-containing material, (ii) contacting the milled chitin-containing material from step (i) with a mixture comprising an aqueous solution of an organic acid, and (iii) contacting the chitin-containing material with an alkaline solution, the alkaline solution comprises water, glycerol and potassium hydroxide with the concentration of 0.2 M to 5M in a ratio of (50-100): (1-50) (v / v); and thereby treating the chitin-containing material. The invention also relates to a chitin formulation, a calcium salt of an organic acid, a protein product or an astaxanthin, which is prepared or can be prepared from a chitin-containing material according to the method of the invention, and to the chitin formulation prepared or can be prepared in the manufacture of natural or synthetic polymers, in agriculture, in packaging, in particular in food packaging. The invention also relates to the use thereof as an ingredient in construction, or in environmental protection, in the preparation of pharmaceuticals, foods or cosmetics, and / or as an immobilized enzyme carrier.

The application relates to the technical field of integrated circuit manufacturing, and discloses wafer thinning equipment and a thinning method. The wafer thinning equipment comprises a grinding device and an adsorption platform. The adsorption platform is used for supporting a wafer and driving the wafer to rotate. The grinding device is arranged above the adsorption platform in a lifting mode. The lower part of the grinding device is provided with a grinding wheel used for grinding the wafer. The grinding wheel comprises a base material and a plurality of grinding blocks. The grinding blocks are fixed to the base material through an adhesive layer. The grinding blocks comprise a gel ceramic combination body which has a staggered spiral stacking structure and is used for dispersing stress during grinding. The raw material of the gel ceramic combination body is a ceramic gel bonding agent which comprises calcium carbonate / calcium phosphate composite gel and chitin nanocrystals. The above technical scheme solves the problems of large total thickness deviation of the thinned wafer and easy formation of a subsurface damage layer in the related art.

This invention provides a flocculant, its preparation method, and its application. The flocculant comprises plant root cellulose, modified chitin, lignin-based copolymer, modified agar, calcium silicate, and montmorillonite. The preparation method includes a one-step mixing of plant root cellulose, modified chitin, lignin-based copolymer, modified agar, calcium silicate, and montmorillonite, followed by uniform stirring to obtain the flocculant. The flocculant provided by this invention achieves efficient flocculation of suspended solids in water while reducing potential environmental impacts, lowering production costs, simplifying the preparation process, and facilitating large-scale application.

The application discloses a kind of multilayer nanostructure hemostatic powder and preparation method thereof, belong to the field of biomedical hemostatic material.To solve the problem of insufficient mechanical strength of existing silk fibroin-polyphenol hemostatic material, the silk fibroin solution is mixed with regenerated chitin nanofiber solution in proportion, and tea polyphenol solution is added dropwise to induce co-assembly and gelation, and the powder is prepared by washing, freeze-drying and grinding.The powder can quickly absorb water and self-gel after contacting with blood, and form a stable three-dimensional network hydrogel within a few seconds.The regenerated chitin nanofiber guides the formation of hierarchical nanostructure of silk fibroin through supramolecular interaction, significantly enhances the mechanical strength and adhesion, while tea polyphenol provides antibacterial, antioxidant and procoagulant functions.The hemostatic powder of the application has the functions of rapid hemostasis, strong adhesion in wet state, resistance to flushing and promotion of wound healing, and is suitable for various acute bleeding scenarios.

The use of insect litter in combination with mushroom cultivation results in superior results, such as increased yield, reduced greenhouse gas emissions, as compared to mushroom cultivation without using insect litter. Use of insect litter during mushroom cultivation may provide synergistic improvement results relative to cultivation of mushrooms or production of insects and insect litter without the other. By using mushrooms and / or by-products thereof and insect litter and components thereof in combination, a closed-loop system can be created that will provide beneficial results to humans, including but not limited to reduced greenhouse gases, more employment opportunities, synergistic effects associated with improved protein and other nutrient production and yield, as well as the use of mushrooms and / or by-products thereof and insect litter and components thereof. And / or higher mushroom yield.

This invention discloses a method for cultivating pearl grouper, belonging to the field of aquaculture technology. Through careful design of active component configuration and juvenile feeding according to size, component A includes the following raw materials: β-chitosan, oxalic acid, and *Gnaphalium affine* extract; component B includes the following raw materials: sugarcane extract, rye seed powder, and oryzanol; component C includes the following raw materials: fig polysaccharide, yeast β-glucan, and eucalyptus oil. When the juvenile size is 2.2~5.0cm, a basic feed supplemented with components A and B is provided; when the juvenile size is 5.1~10cm, a basic feed supplemented with components A and C is provided; when the juvenile size is greater than 10cm, a basic feed supplemented with components A, B, and C is provided. The cultivation method of this application can improve the resistance of pearl grouper to *Vibrio harveyi* infection and / or its low-temperature tolerance, and the cultivation method is simple and the raw materials are readily available.

This invention relates to a method for preparing carbon nanoflower-coated bismuth electrode materials for fast-charging batteries, belonging to the field of new energy electrode material preparation technology. The invention involves adding bismuth oxide and chitin-like substances to deionized water and ultrasonically dispersing them to obtain a mixed solution. The mixed solution is then sealed in a reaction vessel and subjected to a high-temperature, high-pressure reaction, followed by solid-liquid separation to obtain the reaction product. The reaction product is calcined under a protective or reducing atmosphere to obtain the carbon nanoflower-coated bismuth electrode material. This carbon nanoflower-coated bismuth electrode material is a core-shell material, with a bismuth core and an outer shell of N-doped carbon nanoflowers, on which bismuth nanoparticles are loaded. The nanoflower coating layer of this invention exhibits high electrolyte permeability and wettability, buffering the volumetric expansion of the internal bismuth electrode during charging and discharging. The bismuth nanoparticles loaded on the carbon nanoflowers effectively improve the electrode's diffusion kinetics. The carbon nanoflower-coated bismuth electrode material possesses a large volumetric capacity and excellent fast-charging performance.

The application discloses a photonic film coating, a preparation method and application. Chitin nanowhiskers are compounded with polyvinyl alcohol to obtain the photonic film coating; the chitin nanowhiskers are extracted from shellfish waste; and the mass ratio of the chitin nanowhiskers to the polyvinyl alcohol is 0.1-1:1. The photonic film coating is low in cost, natural and non-toxic, simple in process equipment and operation, and capable of realizing rapid and large-area photonic film preparation, and can be widely applied to multiple fields such as automobile decoration, building decoration and anti-counterfeiting.

The utility model belongs to the technical field of water-soluble fertilizer wastewater treatment devices, and particularly relates to a wastewater treatment device in chitin fertilizer production, which adopts the following scheme that the wastewater treatment device comprises a treatment box, the separation plate is fixedly mounted at the bottom of the inner cavity of the treatment box; the two sides of the rear side of the inner cavity of the treatment box are rotationally connected with the stirring rod; the two sides of the rear side of the treatment box are fixedly connected with the motor, and an output shaft of the motor penetrates into an inner cavity of the treatment box and is fixedly connected with the rear side of the stirring rod; the two sides of the top of the treatment box communicate with the medicine inlet pipe; according to the sewage treatment device, water can be injected into the two sides of the separation plate in batches through matched use of the adjusting mechanism, after sewage on one side of the separation plate is treated, a worker cleans the precipitation box and then injects water into the precipitation box, the continuity of wastewater treatment is improved, and then the efficiency of wastewater treatment is improved.

This application discloses a one-pot method for preparing nano-chitosan using a eutectic solvent, comprising the following steps: mixing oven-dried marine waste powder with a eutectic solvent, reacting, adding a mixed solution of alcohol and water, precipitating, centrifuging, separating the resulting solid, diluting, dialysis, centrifuging, and separating again to obtain upper chitosan nanowhiskers (ChNC) and lower chitosan nanocrystal bundles (ChSR). This method simultaneously recovers chitosan nanowhiskers (ChNC) and ChSR (chitosan solid residue), and homogenizes the ChSR to obtain chitosan nanofibers, minimizing chitosan loss and maximizing total yield. The prepared chitosan nanowhiskers and chitosan nanofibers can be applied to polymer reinforcement, food packaging, water treatment, and drug delivery, among other applications.

The invention provides a high-activity exo-chitinase mutant and application of the high-activity exo-chitinase mutant in degradation of chitin waste, and belongs to the technical field of enzyme engineering and waste bioconversion. According to the present invention, the semi-rational engineering design is performed on the wild type exo-chitinase derived from Paenibacillus barengltzii, and a group of exo-chitinase mutants with characteristics of high activity, high stability and strong substrate binding affinity are constructed through the site-directed mutagenesis and domain fusion strategy; the exo-chitinase mutant shows excellent thermal stability and pH stability in a wide temperature and pH range, and the exo-chitinase mutant or an enzyme preparation containing the exo-chitinase mutant can be used for large-scale degradation of agricultural and marine chitin wastes. The method has a wide application prospect in the fields of sustainable feed production, agriculture and industrial biotechnology.