161 results about "Toxic chemical" patented technology

The invention provides a preparation method of an environment-friendly preservative for preparing a dog fur specimen, and belongs to the field of animal specimen preparation. According to the preservative, natural plant extracts are combined with low-toxicity chemical components, so that the original color and form of a specimen can be kept, and excellent corrosion resistance, mildew resistance and worm damage resistance are provided. Compared with a traditional formaldehyde preservative, the preservative disclosed by the invention has the advantages of low toxicity, small smell, safety in operation and the like, and is suitable for long-term preservation of marine animal specimens in museums, scientific research institutions and related units.

The invention belongs to the technical field of functional food processing, and particularly relates to a method for synergistically improving functional characteristics by utilizing casein peptide and hydroxytyrosol self-assembly. According to the research, casein peptide with an excellent antioxidant function is used as a raw material, and hydroxytyrosol is added to be self-assembled with the casein peptide, so that the antioxidant activity is synergistically improved in an in-vitro digestion stage. Compared with a traditional protein and polyphenol combination technology, the casein peptide and polyphenol self-assembly method is provided, the antioxidant activity after digestion is improved, no toxic chemical reagent is introduced or added, and the casein peptide and polyphenol self-assembly method is safer, more efficient, more environmentally friendly and more sustainable. The method can be widely applied to functional food or health care products.

A pre-stressed pultruded glass fiber reinforced thermoplastic lumber suitable for demanding construction environments, particularly marine and outdoor applications, features a solid core composed of a thermoplastic, such as PVC, blended with 15% to 40% by weight of pelletized chopped strand glass fibers. Pre-tensioned elongated continuous fiber reinforcements are embedded within and coextensive with this core via pultrusion. The presence of pelletized and fragmented glass fibers within the core enhances the mechanical coupling between the core and the continuous reinforcements, facilitating the transfer of tensile stress to the core as compressive pre-stress. An outer co-extruded cap stock provides protection against UV and IR radiation and enhances impact resistance. The resulting lumber exhibits a high modulus of elasticity (exceeding 800,000 psi), at least 60% fiber length retention, improved durability, and resistance to common wood degradation factors without the use of toxic chemicals.

The invention discloses starch-collagen composite hydrogel as well as a preparation method and application thereof. Collagen is catalyzed by microbial transglutaminase to form a covalent cross-linked network, and meanwhile, hydroxypropyl starch is introduced to construct a physical interpenetrating network through molecular chain penetration and hydrogen-bond interaction; and chondroitin sulfate is further integrated to strengthen the network structure and biological activity through electrostatic interaction. The method is mild in condition and does not need a toxic chemical cross-linking agent, the obtained composite hydrogel has an interpenetrating double-network structure and has excellent mechanical properties, enzymatic degradation resistance and cell affinity, the compression modulus of the composite hydrogel is remarkably improved, the composite hydrogel can keep structural stability for a long time in a collagenase environment, cell adhesion and proliferation can be effectively promoted, and the composite hydrogel has a good application prospect. The hydrogel can be widely applied to tissue engineering scaffolds, wound dressings, drug sustained-release carriers and cartilage repair materials.

The application relates to a method for one-step synthesis of strong magnetic hydrophobic Fe3O4 nanoparticles at low temperature and the Fe3O4 nanoparticles and application, and belongs to the technical field of nano material preparation. The method comprises the following steps: adding a ferrous sulfate solution into a mixed solution of sodium hydroxide and sodium nitrate, heating and stirring to react, adding oleic acid in the reaction process, and obtaining black Fe3O4 crystals after the reaction is completed. The saturation magnetization of the obtained strong magnetic hydrophobic Fe3O4 nanoparticles can reach 85.69 emu / g at most, and the water contact angle can reach 148.95 DEG. The one-step synthesis reaction only needs to use oleic acid as a regulator, avoids an extreme high-temperature and high-pressure environment, does not need to use a toxic chemical solvent, the condition is mild, the process is simple, the operation condition is easy to control, and the method has a wide application prospect.

The invention relates to the technical field of plant polysaccharides, and particularly discloses a red-knees herb polysaccharide and a preparation method and application thereof, the peak top molecular weight of the red-knees herb polysaccharide is 33.9 KDa, the weight-average molecular weight of the red-knees herb polysaccharide is 42.8 KDa, the number-average molecular weight of the red-knees herb polysaccharide is 10.0 KDa, and the red-knees herb polysaccharide is mainly composed of galacturonic acid, galactose, arabinose, rhamnose and glucuronic acid. According to the preparation method of the red-knees herb polysaccharide, by optimizing process parameters and controlling the reasonable solid-liquid ratio, heating temperature and heating time, the dissolution rate of the polysaccharide is increased, the dissolution rate of impurities is reduced, and the yield of the red-knees herb polysaccharide is increased. The red-knees herb polysaccharide is used as a raw material, ethanol is used for alcohol precipitation, polysaccharide components are precipitated, impurities are preliminarily removed, then macroporous resin is used for purification, the recovery rate of polysaccharide and the removal rate of impurities such as pigment and protein are improved by screening optimization and pretreatment of the macroporous resin, and the total sugar content of the purified red-knees herb polysaccharide is 80% or above. Use of toxic chemical reagents is avoided, and the preparation method is safe and efficient.

The invention provides a composition containing arbuscular mycorrhizal fungi (AMF) and charcoal and application of the composition in improvement of cadmium tolerance of tobacco and / or improvement of soil, and belongs to the technical field of biological agriculture. The AMF is combined with the biochar to be applied, so that the growth of the tobacco can be effectively promoted, the agronomic traits and biomass of the tobacco can be improved, meanwhile, the resistance of the tobacco to cadmium can be effectively improved, cadmium accumulation in the tobacco is effectively reduced, subcellular distribution of cadmium in the tobacco body is changed, and high-toxicity chemical-state cadmium is converted into toxic or low-toxicity cadmium; the soil environment and nutrients can be improved, the antioxidant enzyme activity can be regulated, and a better soil environment is provided for the growth of the tobacco.

The invention discloses a nanofiber based on a polypeptide derivative and an enzymatic self-assembly method and application of the nanofiber based on the polypeptide derivative, the sequence of the polypeptide derivative is Nap-Gly-Phe-Phe-pTyr-Lys-Trp-Tyr-Gln-Asn-Met-Ile-Arg, and the Gly-Phe-Phe-pTyr is of an L configuration or a D configuration. The self-assembled polypeptide derivative disclosed by the invention contains an alkaline phosphatase restriction enzyme cutting site, and the self-assembled polypeptide derivative is self-assembled at a specific part with high enzyme specificity expression through enzyme catalysis to form nanofibers. The nanofiber hydrogel obtained through enzymatic treatment is carried out under physiological conditions, high temperature or ultraviolet irradiation is not needed, damage of high temperature to bioactive substances is avoided, the nanofiber hydrogel is more suitable for a temperature-sensitive in-vivo environment, toxic chemical cross-linking agents or photoinitiators do not need to be introduced, the cytotoxicity of the material is remarkably reduced, active enzymes or drugs can be embedded in situ, and the nanofiber hydrogel can be used for in-situ treatment. The biological function is maintained.

The invention provides a water evaporation power generation device based on an MXene / filter paper composite film and a preparation method, and belongs to the technical field of water evaporation power generation. The preparation method comprises the following steps: adding FeCl2. 4H2O or FeSO4. 7H2O and ascorbic acid into a mixed solution of ethylene glycol and water, and stirring under a water bath condition to obtain an etching solution; slowly adding MAX powder into the etching solution, and carrying out magnetic stirring etching reaction to obtain a product solution; performing centrifugation, suction filtration and drying treatment on the product solution to obtain MXene solid powder; dissolving the solid powder in deionized water to form a solution, and carrying out suction filtration treatment on the solution on filter paper to obtain an MXene / filter paper composite film; the conductive parts are connected to the upper end and the lower end of the MXene / filter paper composite film, the water evaporation power generation device is obtained, the MXene stripping process is simple, the subsequent complex treatment process is not needed, and strong acid and virulent chemicals are not contained.

The invention provides a stepped directional extraction method of fucoidan, and relates to the technical field of extraction of active ingredients of algae. The method comprises the following steps: pretreating brown algae powder by microwaves and ultrasonic waves, mixing the pretreated brown algae powder with a deep eutectic solvent, and carrying out ultrasonic extraction to obtain algin; the eutectic solvent is composed of choline chloride and lactic acid according to the molar ratio of 1: (1-3). According to the method disclosed by the invention, a microwave-ultrasonic synergistic wall-breaking coupling deep-eutectic solvent extraction process is adopted, so that the yield of algin is increased to 73.2%, meanwhile, an additional toxic chemical chelating agent does not need to be added, the effect of effectively adsorbing heavy metal ions is achieved, and the biological safety and commercial value of the product are greatly improved.

The process for producing and using polymeric Hydrocells for production of atmospheric water using a superabsorbent polymer derived from alkaline hydrolysis of the polyacrylonitrile (PAN). The Hydrocell adsorbs up to 80% of its weight in atmospheric water under ambient conditions and releases this water when heated to less than 100° C. using renewable energy sources, such as solar energy. This low-temperature operation allows for repeated adsorption and desorption cycles lasting years without degradation. Multiple Hydrocells can be arranged into Hydrobatteries with a surface area greater than 2 m2, capable of adsorbing several kg of water per day. The Hydrocells offer a sustainable and safe solution for producing potable water free of toxic chemicals and pathogenic microorganisms in regions with limited water resources. By drawing water from the vast atmospheric reservoir containing over 13,000 km3, this can help prevent deaths caused by the consumption of contaminated water.

The application discloses an injectable microsphere gel of controllable performance silk protein and a preparation method thereof, and belongs to the field of biomaterials.The preparation method comprises the following steps: preparing a regenerated silk protein solution, including degumming, dissolving and purifying of mulberry silk, and obtaining a regenerated silk protein solution with a target molecular weight through molecular weight screening; preparing a silk protein microsphere aqueous solution by adding ethanol to the regenerated silk protein solution and performing freezing and thawing; obtaining a silk protein microsphere redispersible powder by drying two solutions prepared in the above steps; and preparing a silk protein microsphere gel by dispersing the silk protein microsphere redispersible powder in a solvent and adding a gel inducer.The whole preparation process does not involve toxic chemical reagents, and thus the excellent mechanical properties, ideal biocompatibility and biodegradability of the material are ensured; the silk protein microsphere gel has thixotropy, can be injected into subcutaneous tissue through a syringe, has a certain self-supporting property after injection, has controllable mechanical properties due to the molecular weight screening, and can be used in different application scenarios.

The invention relates to an environment-friendly process method for improving the surface metal cleaning efficiency of a silicon wafer, and belongs to the technical field of semiconductor silicon wafer processing, and the process method comprises the following operation steps: S1, pre-cleaning and activation: placing the silicon wafer in a first cleaning tank, introducing ozone into ultrapure water, and processing in cooperation with low-frequency ultrasound; and S2, main cleaning and complexing: placing the silicon wafer subjected to pre-cleaning and activating treatment in a second cleaning tank, and treating the silicon wafer in a dilute citric acid solution in cooperation with high-frequency ultrasound. And S3, overflow rinsing: placing the silicon wafer subjected to main cleaning and complexing treatment in a third cleaning tank. And S4, drying: carrying out drying treatment on the silicon wafer subjected to the overflow rinsing treatment. Through the synergistic effect of physical stripping, chemical oxidation and complexing dissolution, under the condition that highly toxic chemicals such as hydrofluoric acid are not used, the cleanliness of metal on the surface of the silicon wafer reaches the ppt level, and the problems that traditional RCA cleaning is serious in environmental pollution and high in operation risk are effectively solved.

The invention belongs to the technical field of synthesis of pesticide intermediates, and discloses a preparation method and application of indazole carboxylic acid. The preparation method of the indazole carboxylic acid comprises the following steps: (1) cyanation reaction: reacting a brominated indazole compound with cuprous cyanide in an organic solvent in a protective gas atmosphere to obtain a cyano indazole compound; and (2) hydrolysis reaction: hydrolyzing the cyano indazole compound prepared in the step (1) to obtain indazole carboxylic acid. The preparation method disclosed by the invention is mild in condition, low in cost, safe to operate and environment-friendly. The use of highly toxic chemical raw materials and expensive raw materials is avoided, and the yield of the target product is high.

This invention belongs to the interdisciplinary field of biomedical engineering, materials science, and tissue engineering, and discloses a multifunctional hydrogel with switchable mechanical and adhesive properties based on temperature triggering, its preparation method, and applications. The invention consists of acrylic acid, gelatin, hexadecyltrimethylammonium bromide, polydopamine nanoparticles loaded with silver nanoparticles, and water. This invention not only exhibits excellent adhesion and mechanical properties to skin tissue but also possesses switchable mechanical and adhesive properties, achieving durable and repeatable adhesion. The temperature-triggered hydrogel prepared by this invention is simple to process, low in cost, and introduces no toxic chemicals. It can achieve a close fit at body temperature and natural detachment at low temperatures, driven by temperature, and maintains excellent adhesion properties even in complex environments, thus promoting the development of intelligent medical multifunctional wound dressings.

The application discloses a kind of positive charge biomass carbon dots and preparation method and application thereof, belong to biomass carbon dot technical field.The application provides a kind of method for preparing nanoscale biomass carbon dots with positive charge using agricultural waste-tomato seedling, and the preparation method is simple and easy to operate, and the equipment requirement is low, material source is extensive, cheap and easy to obtain, no toxic chemical reagent is used, and it is environment-friendly, and the preparation cost is low;A new way for high-value utilization of tomato seedling is provided;The biomass carbon dots prepared are approximately spherical in shape, uniform in size, well dispersed, and have no aggregation phenomenon, with an average diameter of 10 nm and an average potential of +42.03 mV;Good hydrophilicity, strong stability;With blue, green, red and other fluorescent properties.

A system for removing toxic chemicals from Refined Bleached Deodorized Oil (RBDPO), comprising: a treatment section comprising a sorbent for removing toxic chemicals from the RBDPO; a regeneration section for separating the treated RBDPO from the adsorbent, thereby regenerating the adsorbent; wherein the adsorbent comprises a material functionalized with a silane coupling agent such that when a toxic chemical from the RBDPO contacts the functionalized adsorbent, a chemical bond is formed between the toxic chemical and the adsorbent, thereby enabling separation of the toxic chemical from the RBDPO and subsequent removal of the toxic chemical from the RBDPO. A process is also disclosed herein.

This invention discloses a diatomaceous earth-based graphene composite aerogel, its preparation method, and its applications. The preparation method includes: preparing a graphene oxide dispersion; pretreating unmodified natural diatomaceous earth; mixing the graphene oxide dispersion with the pretreated diatomaceous earth and then performing a hydrothermal reaction to obtain a hydrogel; freeze-drying the hydrogel to obtain an aerogel precursor; and annealing under an inert atmosphere to obtain the target aerogel. This invention uses unmodified natural diatomaceous earth, avoiding the surface modification steps in traditional processes, simplifying the preparation process, and reducing production costs. Combined with annealing, it eliminates the need for toxic chemical reducing agents, making the process green and environmentally friendly. The resulting composite aerogel possesses both lightweight and structurally stable properties, showing promising application prospects in water treatment, thermal insulation, and electrochemical energy storage.

The application provides a phosphorus modified zero-valent iron catalytic material, a preparation method, a remediation agent and application. 3‑ The phosphorus modified zero-valent iron catalytic material is obtained, wherein the particle size of the zero-valent iron is micron level. The preparation method of the application can be completed in an air atmosphere, and does not need high temperature, vacuum or addition of toxic chemical reagents. The preparation process only involves physical mixing and mechanical ball milling, the equipment requirement is simple, the operation is convenient, the energy consumption is low, the dual benefits of environmental governance and ecological restoration are combined, and the green and sustainable development environmental governance concept is met.

The application discloses a method for preparing high-brightness multi-color luminescent IRMOF-0 material, and belongs to the technical field of multi-color luminescent metal organic framework (MOFs) material. The method comprises the following steps: taking non-luminescent IRMOF-0 as initial material, pre-pressing a T301 stainless steel gasket by using a diamond anvil, then forming a micro-hole sample cavity with a diameter of about 120 microns at the center of the concave pit generated by pre-pressing by using a laser punch, putting the non-luminescent IRMOF-0 initial material into the sample cavity, putting a ruby ball into the sample cavity, calibrating the pressure in the sample cavity by using a ruby fluorescence spectrum, applying a pressure of 6-30 GPa to the diamond anvil, and then releasing the pressure of the diamond anvil to normal pressure, so as to obtain the IRMOF-0 material with bright and multi-color luminescent characteristics. The method has the advantages of simple preparation and environmental protection, and replaces a complex and toxic chemical synthesis process, thereby opening up a new application prospect for non-aromatic interpenetrating MOFs.

The invention discloses a production process of N-acetylglucosamine, and belongs to the technical field of N-acetylglucosamine production. Methanol is used as a solvent, glucosamine hydrochloride and acetic anhydride are used as raw materials, sodium hydroxide is added as a catalyst, other toxic chemical substances are not introduced, and meanwhile, the product yield is increased. In addition, in the product purification treatment process, a specific fixing agent is added, the specific fixing agent is a magnetic nanoparticle immobilized phenylboronic acid derivative, and the phenylboronic acid derivative can recognize and combine D-glucosamine with cis-dihydroxyl and cannot react with N-acetylglucosamine; the D-glucosamine in the N-acetylglucosamine can be effectively and selectively removed; and after the magnetic nanoparticles are immobilized, the selective adsorption reaction can be amplified, the separation and removal are facilitated, and the operation steps are simplified.

This invention relates to the field of textile processing technology, specifically to a method for preparing hydrophobic PET fabrics via an enzymatic process, and the resulting fabric. The invention pre-activates the surface of the PET fabric using an enzymatic method, followed by an amidation reaction with a long-chain fatty amine in the presence of a condensing agent, constructing a covalently fixed alkyl hydrophobic layer. Compared to traditional surface treatments or coatings using alkalis, the method provided by this invention offers milder processing conditions, eliminating the need for large amounts of toxic chemical reagents. Furthermore, the PET hydrolase used in this method exhibits mild action, high selectivity, and high specificity, preferentially attacking the amorphous regions of PET with minimal impact on the crystalline structure and mechanical properties of the PET fibers. This achieves a balance between surface modification and mechanical properties, which is of significant importance for the subsequent functional finishing of PET fibers.

This invention belongs to the technical field of oil and gas extraction, and relates to a high-deformation temporary plugging agent and its preparation method, specifically including the following steps: Step 1, preparing modified cellulose; Step 2, preparing PLA / ZnO composite; Step 3, placing TPU, tributyl citrate, modified cellulose, PLA / ZnO composite, four-arm PEG and antioxidant into a processing device in batches according to a certain ratio; Step 4, performing electron irradiation treatment to obtain the high-deformation temporary plugging agent; This invention achieves both high deformation and high strength through a multi-level synergistic design of a rigid cellulose skeleton + flexible TPU matrix + PLA microcrystalline reinforcement points, and solves the particle shedding problem through three key technologies: supercritical CO2 foaming embedding, staged twin-screw mixing, and simultaneous electron irradiation crosslinking; and establishes a green temporary plugging system by replacing toxic chemicals with bio-based plasticizers and irradiation crosslinking.

The invention belongs to the technical field of photocatalysts, and particularly relates to an ultrathin porous carbon nitride nanosheet as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out electrochemical auxiliary liquid-phase chemical stripping treatment on blocky g-C3N4 to obtain an ultrathin porous g-C3N4 nanosheet; and the electrolyte comprises a NaClO solution. According to the preparation method disclosed by the invention, blocky g-C3N4 is delaminated into the ultrathin porous g-C3N4 nanosheet by adopting a strategy of electrochemistry assisted liquid-phase chemical delamination and utilizing a synergistic effect of a Na < + > alkali metal embedded delamination layer and a ClO <-> chemical oxidation induced delamination layer in an electrolyte. The electrochemically-assisted chemical stripping treatment involved in the method is simple to operate, chemical reagents are low in cost, nontoxic and harmless, and the high-quality ultrathin porous g-C3N4 nanosheet material can be efficiently obtained.

The utility model discloses an insect trapping device, which belongs to the technical field of biological science and comprises a folding plate and a trapping component. Wherein the folding plate comprises a plurality of plate bodies which are sequentially connected, every two adjacent plate bodies are arranged in a bent mode in the first linear direction at an included angle, every two plate bodies located at the head end and the tail end of the folding plate are detachably connected, the multiple plate bodies define a containing space, and the two sides, in the second linear direction, of the containing space are each provided with an opening. The opening is communicated with the accommodating space and the outside; the trapping assembly comprises an insect sticking plate and bait, the insect sticking plate is detachably arranged in the containing space, the bait is detachably arranged on the insect sticking plate, and the insects cannot move after making contact with the insect sticking plate. The device does not depend on toxic chemical substances, threats to human health and pollution to the environment are avoided, and the device is more environmentally friendly and safer and has high capture efficiency.

The application belongs to the technical field of circuit boards, and discloses a preparation method of a graphene conductive liquid for a circuit board hole metallization process, which takes an environment-friendly graphene as a core material, does not add toxic chemical reagents in a preparation process, realizes hole wall conductive layer construction through electrostatic adsorption in application, does not involve harmful chemical reactions, and eliminates environmental pollution from the source; meanwhile, the process does not need a palladium catalyst, and graphene raw materials can be prepared at low cost based on natural flaky graphite, are matched with the characteristics of solution stability and easy maintenance (not stratified for months in natural storage), greatly reduce reagent replacement and equipment maintenance frequency, reduce comprehensive production cost, meet global environmental protection policy requirements, and create economic value for enterprises; through hierarchical airflow-wet method collaborative crushing, the number of graphene layers is accurately controlled, and in combination with a 'gradient magnetic field-ultrasonic auxiliary impurity removal' to improve purity, so that the conductive basic performance is guaranteed.

The invention belongs to the technical field of electrode materials, and particularly relates to a manganese-based positive electrode preparation process based on oxygen reduction catalyst modification, which comprises the following steps: preparing a zinc-containing framework material and a manganese-containing framework material; the preparation method comprises the following steps: mixing a zinc-containing and manganese-containing framework material with polyethylene glycol, carrying out a hydrothermal reaction, and calcining a product to obtain ZnMn2O4; and preparing a pole piece by using ZnMn2O4, and carrying out Pt modification on the surface of the pole piece to obtain the ZnMn2O4 / Pt composite material. The manganese-based positive electrode based on oxygen reduction catalyst modification is simple in preparation process, relatively low in cost, safe and simple in operation steps, free of hazardous chemicals in the preparation process and free of strong oxidizing or highly toxic chemicals, has the advantages of environmental friendliness, safety and controllability, and is easy for industrial application.

The invention relates to the technical field of DNA microarrays, and discloses a preparation method and application of a DNA nano array. The preparation method of the DNA nano array comprises the following steps: step 1, acquiring DNA ink, and then transferring the DNA ink to the edge of a substrate material; step 2, moving a flexible platform to enable a probe to be in contact with the DNA ink, then dropping the probe at a first preset position of the substrate material and then lifting the probe to obtain a first DNA nanodot; and 3, changing the target preset position of the substrate material, and repeating the step 2 to obtain the target DNA nanodot. By adopting the method disclosed by the invention, the DNA nano array of which the average diameter is less than or equal to 500 nm, the distance between adjacent points is less than or equal to 2000 nm and the average height is less than or equal to 50 nm can be prepared, the prepared DNA nano array has the characteristics of high density and high flux, meanwhile, the preparation process is simple, the cost is relatively low, and no other toxic chemical reagents are introduced.

The invention discloses an absorbable monofilament suture and a preparation method thereof, and the preparation method comprises the following steps: S1, dissolving chitosan in a dilute acid solution to form a spinning solution; s2, sequentially carrying out filtering treatment and vacuum defoaming treatment on the spinning solution; s3, the spinning solution treated in the step S2 is extruded into a coagulating bath through a spinning component, and nascent fibers are formed; s4, carrying out water washing treatment on the nascent fiber; s5, immersing the nascent fiber treated in the step S4 into a polycarboxylic acid solution to carry out an ionic cross-linking reaction; s6, the fibers subjected to the ionic cross-linking reaction in the step S5 are sequentially subjected to water washing treatment and drying treatment, the absorbable monofilament suture is obtained, the mechanical properties such as dry-state holding stress and the like of the finally obtained monofilament suture are synergistically and remarkably improved, use of a toxic chemical cross-linking agent is avoided, and the production cost is reduced. And the suture is ensured to finally have good biocompatibility and controllable degradation performance.

The invention belongs to the technical field of gene engineering, and discloses a method for synthesizing L-cysteine through whole-cell catalysis, recombinant Escherichia coli and application, and the recombinant Escherichia coli is constructed through the following method: knocking out sdaA and tdcG genes for coding L-serine dehydratase; mutant beta subunit genes are obtained to construct recombinant plasmids, and the recombinant plasmids efficiently overexpress mutant genes and genes trpA in strains to obtain recombinant escherichia coli. The method is mild in reaction condition, low in energy consumption, environmentally friendly and high in substrate utilization rate through an enzyme method, and the overall cost is obviously reduced. The catalytic system can efficiently react at 25-35 DEG C from neutral to alkalescence, high temperature and high pressure or toxic chemical reagents are not needed, and energy consumption and environmental pressure are remarkably reduced. Meanwhile, the reaction system is high in substrate conversion rate and few in side reaction, the utilization rate of raw materials is greatly increased, and the method has obvious economic advantages.