995 results about "Aspartic acid" patented technology

The invention discloses a high-performance carbonyl reductase mutant and application thereof in synthesis of a series of chiral alcohols. The high-performance carbonyl reductase mutant is obtained by performing the following mutations on an amino acid sequence as shown in SEQ ID NO.2: the 69th alanine mutates into any one of lysine, leucine, aspartic acid or asparagine, and the 69th alanine mutates into any one of lysine, leucine, aspartic acid or asparagine; and / or the 100th glycine is mutated into any one of glutamic acid, serine, lysine or asparagine. Compared with a wild type enzyme, the thermal stability and the catalytic activity of the obtained mutant are remarkably improved, particularly, single point mutants Mut-A69N, Mut-G100E and Mut-G100N and a combined mutant Mut-A69N-G100N show excellent relative enzyme activity, thermal stability and substrate tolerance. The mutant has high catalytic activity and stability to various chiral alcohols, and the contradiction that the traditional carbonyl reductase is easy to inactivate at high temperature and the catalytic efficiency is difficult to achieve at the same time is solved. The invention provides an efficient and stable enzyme catalysis tool for green biological preparation of chiral drug intermediates.

The invention discloses a potassium fulvate chelated macroelement water-soluble fertilizer with stress resistance and growth promotion functions, and relates to the technical field of water-soluble fertilizers, the potassium fulvate chelated macroelement water-soluble fertilizer comprises the following raw materials by weight: 167-210 parts of mineral source potassium fulvate, 450-460 parts of potassium nitrate, 300-310 parts of urea, 150-160 parts of potassium dihydrogen phosphate, 30-40 parts of potassium sulfate, 15-25 parts of EDTA-disodium, and 5-15 parts of citric acid. 0.5 to 1.5 parts of brassinolide and 4 to 6 parts of polyaspartic acid; according to the potassium fulvate chelated macroelement water-soluble fertilizer with the stress-resistant and growth-promoting functions, through chelation cooperation of potassium fulvate and nitrogen, phosphorus and potassium, the solubility of the chelated phosphorus element in water is increased, and the chelated phosphorus element can be more uniformly distributed in soil; by adopting an EDTA-disodium and citric acid composite chelating system, volatilization and loss of nitrogen elements are reduced, the problem of precipitation of calcium, magnesium and phosphorus is solved, and the soil conditioner is suitable for hard water areas and especially has outstanding performance in saline-alkali soil and arid areas.

The invention relates to a concrete anti-cracking self-repairing agent in the technical field of building materials, and aims to solve the problem that concrete cracks are difficult to self-repair. According to the technical scheme, the self-repairing agent is characterized by comprising a microbial repairing unit formed by ZSM-5 type zeolite molecular sieve loaded bacillus pasteurii spores, mesoporous silica particles loaded with L-calcium aspartate and Fe3O4 (at) SiO2 core-shell nanoparticles which are fixed through an in-situ polymerization coating layer to form a magnetic thermal response capsule layer coating the surface of the microbial repairing unit, pLGA microspheres containing yeast extract are positioned on an interface of zeolite and hydrogel, and a trehalose-anhydrous calcium chloride eutectic compound is used as a directional mineralization accelerant. The concrete anti-cracking self-repairing agent provided by the invention is mainly used for intelligent identification and self-repairing of concrete cracks, and efficient repairing is realized through a microbial mineralization, calcium ion slow release and magnetic thermal response synergistic mechanism.

The invention discloses a cyclic nonapeptide with repairing and anti-oxidation effects and application of the cyclic nonapeptide, the amino acid sequence of the cyclic nonapeptide is cyclic (arginine-glycine-aspartic acid-serine-arginine-lysine-valine-lysine-serine), the prepared cyclic nonapeptide has the repairing and anti-oxidation effects, and the cyclic nonapeptide has the repairing and anti-oxidation effects. The composition can be applied to preparation of cosmetics with repairing and / or anti-oxidation effects.

The invention relates to a phosphorus-free zinc-free seawater special-purpose scale and corrosion inhibitor, which comprises, by weight, 20-25% of sulfonic acid modified polyaspartic acid, 8-12% of quaternized chitosan, 5-10% of a sulfonate copolymer, 5-10% of polyepoxysuccinic acid, 1-3% of benzotriazole or methyl benzotriazole, 0.5-1% of sodium tungstate, and the balance of deionized water. According to the formula, traditional corrosion inhibitors such as phosphorus and zinc are completely abandoned, functions are achieved through natural polymer derivatives such as sulfonic acid modified polyaspartic acid and quaternized chitosan, and the scale and corrosion inhibitor has the following environmental protection advantages that the scale and corrosion inhibitor does not contain phosphorus and zinc elements at all, and water eutrophication and heavy metal accumulation caused by a traditional phosphorus and zinc formula are avoided.

The invention relates to a composite reverse osmosis membrane acidic cleaning agent, a preparation method and a cleaning process thereof, and belongs to the technical field of environment-friendly water treatment. The cleaning agent comprises the following components in percentage by mass: 4-8% of inorganic acid, 20-40% of organic acid, 1-3% of a surfactant, 0.5-1% of a chelating agent, 0.5-1% of a compound corrosion inhibitor and the balance of deionized water. The composite corrosion inhibitor is formed by compounding 2-mercaptobenzothiazole and the like according to a specific mass ratio, the molecular weight of polyaspartic acid is 5000, and the molar ratio of Zn to Mo in the zinc-molybdate compound is 2: 1. The preparation method comprises the following four steps: firstly preparing a compound corrosion inhibitor premix, then preparing an acidic base solution, and then sequentially adding the components to finally obtain the cleaning solution. According to the cleaning process, a cleaning agent and deionized water are mixed, the membrane flux recovery rate is larger than or equal to 85% through cleaning of a specific process, the reverse osmosis membrane can be effectively cleaned, and the performance of the reverse osmosis membrane can be recovered.

The invention relates to a corrosion and scale inhibitor for TRT and a preparation method of the corrosion and scale inhibitor, and relates to the technical field of chemical reagents. The corrosion and scale inhibitor is prepared from the following components in percentage by mass: 15 to 20 percent of morpholine, 25 to 30 percent of aminoethyl ethanolamine, 15 to 20 percent of 1-hydroxyethyl-2-undecylimidazoline onium salt, 12 to 18 percent of sodium polyaspartate, 8 to 12 percent of itaconic acid-allylsulfonic acid copolymer, 1 to 3 percent of alkyl glycoside and the balance of a mixture of water and glycerol in a mass ratio of 1 to (1 to 3). The corrosion and scale inhibitor disclosed by the invention can synchronously inhibit corrosion of an acid medium and scale deposition of salts such as NH4Cl and the like, and the corrosion inhibition rate and the scale inhibition rate are effectively improved.

The invention belongs to the technical field of bioengineering, and relates to a transaminase mutant, a recombinant genetically engineered bacterium and application of the transaminase mutant in catalytic synthesis of (R)-1-Boc-3-aminopiperidine.The transaminase mutant is obtained by conducting single-point or combined mutation on the 131 site and / or the 197 site of an amino acid sequence shown in SEQ ID NO.2; the mutation sites comprise that the 131 phenylalanine is mutated into aspartic acid, threonine or tyrosine, and / or the 197 lysine is mutated into arginine or leucine. Experimental results show that compared with wild type transaminase, the catalytic activity, the thermal stability and the organic solvent tolerance of the obtained mutants, especially single-point mutants MyTA1-F131Y and MyTA1-K197R and a combined mutant MyTA1-F131Y-K197R, are all remarkably improved, and compared with the wild type transaminase, the catalytic activity, the thermal stability and the organic solvent tolerance of the obtained mutants are all remarkably improved. The mutant MyTA1-F131Y-K197R can be used for efficiently catalyzing asymmetric amination of N-Boc-3-piperidone to synthesize (R)-1-Boc-3-aminopiperidine, the conversion rate of the (R)-1-Boc-3-aminopiperidine after the (R)-1-Boc-3-aminopiperidine reacts for 24 hours under the condition that the substrate concentration is 100 g / L can reach 90% or above, and the mutant MyTA1-F131Y-K197R has a good industrial application prospect.

The invention belongs to the field of preparation of soil conditioners, and particularly relates to a soil loosening and root promoting soil conditioner and a preparation method thereof. A polymer formed by vinyltriethoxysilane, polyacrylic acid and coumarin under the catalytic action of citric acid is mixed with porous powder obtained after crushing and nutrient organic matter, and freeze-drying is performed to obtain the soil-loosening improved fermentation substrate which can be slowly released in soil; polyaspartic acid and acetylchitosamine are cross-linked under the catalytic action of N-hydroxysuccinimide, root-promoting nutrition powder and auxiliary root-promoting components are mixed, and the obtained composite root-promoting agent can significantly promote the growth of plant root systems; a porous structure contained in the protective stability maintaining agent can provide a relatively stable microenvironment for effective components, and the soil loosening and root promoting agent is mixed with the soil loosening and improving fermentation substrate and the composite root promoting agent, so that the prepared soil loosening and root promoting soil conditioner is remarkable in soil loosening and root promoting effect, long-acting and stable, small in dosage, obvious in effect and stable in conditioning effect after being stored.

The invention provides a method for detecting free amino acids in camellia oleosa seed oil, and establishes a method for detecting the free amino acids in the camellia oleosa seed oil based on ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS / MS), which comprises the following steps: pre-treating various amino acids in the camellia oleosa seed oil by using a non-derivation method; the problems of complicated operation, impurity interference and the like caused by derivatization are avoided, the extraction solvent is environment-friendly and economical, the extraction efficiency is high, and the pretreatment time is greatly shortened; then selecting a proper chromatographic column and a mobile phase, separating a plurality of free amino acids under the condition of not introducing excessive derivatization agents and ion pair reagents, and controlling the collection time to be 12 minutes. The method for detecting the free amino acids in the camellia oleosa seed oil has the characteristics of no need of derivatization treatment, simplicity and convenience in operation, high detection efficiency and good sensitivity and accuracy, and can effectively separate and detect 14 free amino acids such as alanine, phenylalanine and aspartic acid in the camellia oleosa seed oil.

This disclosure describes methods for improving umami and meaty flavors of cell-based food products. In particular, the disclosed method includes an amino acid integration method where cultured cells and exogenous amino acids (e.g., glutamic acid and aspartic acid) are combined and heated, resulting in a synergistic improvement of umami flavors. The disclosed method further includes a browning method by which a cell suspension is dehydrated and heated at high temperatures (e.g., greater than 140C) to induce non-enzymatic browning and caramelization reactions in the cell suspension. The cell-based flavoring product can be combined with a food product as a flavor, aroma, and color enhancer. The disclosed methods may use one or both of the amino acid integration method and the browning method to improve organoleptic properties of cell-based food products.

The invention discloses a high-stability carbonyl reductase mutant and application of the high-stability carbonyl reductase mutant in chiral alcohol synthesis. An amino acid sequence as shown in SEQ ID NO.2 is mutated as follows: 20th leucine is replaced by any one of lysine, threonine, aspartic acid or isoleucine, and / or 55th leucine is replaced by any one of methionine, serine, lysine or isoleucine, and / or 55th leucine is replaced by any one of methionine, serine, lysine or isoleucine. Compared with a wild type enzyme, the stability of the obtained mutant is remarkably improved, particularly, single-point mutants Mut-L20I and Mut-L55I and a combined mutant Mut-L20I-L55I show excellent relative enzyme activity, thermal stability and substrate tolerance. The mutant has high catalytic activity and stability to various chiral alcohols, has the advantages of high catalytic efficiency, high thermal stability, strong substrate tolerance, easiness in fermentation production and the like, and is suitable for industrial application of enzymatic synthesis of chiral alcohols.

The invention relates to the technical field of cleaning agents, and discloses a biodegradable environment-friendly cleaning agent, which comprises: a composite surfactant system comprising at least one nonionic surfactant, an ampholytic surfactant and a chelating functional surfactant; the plant extract oil system comprises limonene and a eucalyptus oil mixture; the functional particle system comprises nanoscale enzyme microcapsules and slow-release type oxidized particles; the natural polysaccharide stable network system comprises at least two polysaccharide thickeners and a bio-based cross-linking agent, and the assistant system comprises a metal ion chelating agent, a buffer acid system and water. By introducing sodium polyaspartate as a green chelating surfactant, efficient chelating of calcium and magnesium ions under a hard water condition is realized, the cleaning power is remarkably improved, water stain residues are reduced, and the cleaning performance with wider adaptability is obtained.

The present invention relates to antisense oligonucleotides (AONs) that can mediate RNA editing by binding to a target RNA nucleic acid molecule, preferably an RNA transcript molecule, in a cell and recruiting an endogenous deaminating enzyme in the cell to deaminate a target adenosine in the target RNA molecule to an inosine. The target RNA molecule is a transcript molecule form the SLC10A1 gene that encodes the Na+ / Taurocholate Co-transporting Polypeptide (NTCP), and the target adenosine is the adenosine in the GAC codon coding for aspartic acid (D) at position 24 of the NTCP protein. The deamination of the adenosine changes the amino acid to a glycine (G). The RNA editing of the adenosine will result in a loss-of-function of the NTCP protein, which will result in lowered uptake of bile acids from the portal circulation into the liver, thereby lowering the risk of suffering from disorders related to bile accumulation in the liver.

The present application relates to a pyridoxal kinase mutant, a recombinant expression vector and a microbial cell and their applications, and belongs to the technical field of biological catalysis. In order to solve the problem of low product concentration in existing enzyme catalysis, a pyridoxal kinase mutant is provided, the amino acid sequence is selected from the amino acid sequence shown in SEQ ID NO. 1, the lysine at position 229 is mutated to alanine, phenylalanine, methionine, arginine, threonine, histidine, serine, tyrosine, valine, leucine, isoleucine, proline, asparagine, aspartic acid or glutamic acid; the pyridoxal kinase mutant is used for catalyzing pyridoxal to synthesize pyridoxal phosphate, and a recombinant expression vector and a microbial cell can be further formed. The present application has good enzyme activity, high product conversion rate, high concentration of pyridoxal phosphate obtained, and the concentration of the product catalyzed by the wild-type pyridoxal kinase to phosphorylate pyridoxal is obviously improved.

The invention relates to the technical field of adhesives, and particularly discloses a low-formaldehyde environment-friendly adhesive and a preparation method thereof. The invention relates to a low-formaldehyde environment-friendly adhesive which is prepared from the following raw materials in parts by mass: 30-50 parts of modified starch, 15-25 parts of vegetable protein, 5-10 parts of modified nano cellulose, 2-5 parts of a composite cross-linking agent and 80-150 parts of water, the composite cross-linking agent comprises amino silane and polyaspartic acid; the modified starch is prepared by performing graft copolymerization on starch subjected to enzymolysis by alpha-amylase and composite anhydride; the vegetable protein is subjected to alkalization and heat treatment before being used; the modified nano-crystalline cellulose is prepared by performing ring-opening etherification reaction on nano-crystalline cellulose, epoxypropane and ethylene oxide in sequence. The low-formaldehyde environment-friendly adhesive prepared by the invention has relatively good bonding strength and relatively low formaldehyde emission.

The invention relates to the technical field of sewage treatment, in particular to a preparation method of a degradable bactericide for an oil field. According to the invention, a hydroxypropyl guanidine gum-polycaprolactone-ethylenediamine fragment copolymer is taken as a carrier, a methylisothiazolinone quaternary ammonium salt (Q-MIT) bactericide is loaded, and the degradable bactericide for the oil field is obtained by cooperating with a dodecyl ethyl sulfide (TC-SE) bactericide and combining with sodium polyaspartate. A carrier forms a hydrogen bond with a polar group on the surface of a biological membrane through a hydroxypropyl guanidine gum main chain to realize targeted anchoring, a polycaprolactone branched chain encapsulates Q-MIT through a hydrophobic effect, primary amino groups of ethylenediamine are introduced to form a pH sensitive Schiff base bond with Q-MIT, and the primary amino groups and adipic dihydrazide form a thermal response hydrazide bond to construct a dual dynamic covalent bond, so that controlled release of Q-MIT is realized, and the biomembrane is prepared. And moreover, the components of the whole system are connected through degradable chemical bonds, so that the environmental protection property and sustainability of oil field operation are guaranteed.

A composition, comprising a D-amino acid oxidase (DAAO) inhibitor and a N-methyl-D-aspartate (NMDA) modulator. Also provided herein are the method of the uses of by administering to a subject in need thereof an effective amount of the composition.

The invention provides a beta-alanine producing strain as well as a construction method and application thereof. According to the bacterial strain, an acetaldehyde dehydrogenase gene adhE, a lactic dehydrogenase gene ldhA, an acetokinase gene ackA, a pyruvate dehydrogenase gene poxB, a DNA binding transcription inhibition factor coding gene lacI, an aspartate kinase thrA, a pantothenic acid synthase gene panC, an alanine synthesis transaminase gene cycA and an alanine synthesis transaminase gene yfbQ are knocked out from an E.coli W3110 genome, and the bacterial strain is obtained. A phosphoenolpyruvate carboxylase gene ppc, a pyridine nucleotide transhydrogenase coding gene pntAB, an aspartic acid transaminase gene aspC, an aspartic acid decarboxylase gene panD derived from pseudomonas aeruginosa and a beta-alanine transporter gene NCgl0580 derived from corynebacterium glutamicum are integrated at the same time, and the bacillus subtilis is used for producing beta-alanine and has the advantage of high fermentation yield.

The invention provides an electrolyte additive for synergistically regulating and controlling activity and stability of an all-vanadium redox flow battery and application of the electrolyte additive, the electrolyte additive is a composite additive of an organic amino acid compound and inorganic phosphate, the organic amino acid compound is one of aspartic acid, glycine and cysteine, and the inorganic phosphate is one of amino acid, glycine and cysteine. The inorganic phosphate is one or two or more of phosphate, dihydric phosphate, dihydric phosphate, polyphosphate and pyrophosphate, and cations of the inorganic phosphate are one or two or more of potassium, sodium and ammonium salt. The composite additive is used as an electrolyte additive to be added into an all-vanadium redox flow battery electrolyte, so that the vanadium electrolyte can be effectively prevented from generating precipitates at high temperature, the capacity fading in the battery operation process is avoided, and the stable operation of the battery is realized. The preparation process is simple to operate, energy-saving, environment-friendly and low in cost, and stable operation of the electrolyte in the battery can be realized.

In the first aspect, the present disclosure provides a Lactoferrin polypeptide fragment, where the Lactoferrin polypeptide fragment has an amino acid sequence shown in SEQ ID NO: 1. In the second aspect, the present disclosure provides a preparation method of the Lactoferrin polypeptide fragment, including: protecting amino acids using a 9-fluorenylmethoxycarbonyl (Fmoc) protecting group, coupling the amino acids with a P-hydroxymethylphenoxymethyl polyethylene resin (HMP resin) in an order of cysteine, alanine, leucine, cysteine, glutamate, threonine, asparagine, aspartate, asparagine, phenylalanine, leucine, leucine, asparagine, and lysine, and separating the HMP resin to obtain a target Lactoferrin polypeptide fragment. In the third aspect, the present disclosure further provides an anti-Lactoferrin antibody prepared using the Lactoferrin polypeptide fragment, and use of the Lactoferrin polypeptide fragment in preparation of an anti-Lactoferrin flow cytometric antibody and in preparation of a Lactoferrin detection product.

The invention provides a polymorphic zinc and organic acid composition for targeted scalp barrier repair as well as a preparation method and application of the polymorphic zinc and organic acid composition. The composition is prepared from the following components in percentage by mass: 1 to 80 percent of yeast / zinc fermentation product, 1 to 20 percent of polyaspartic acid chelated zinc, 0.5 to 20 percent of gluconolactone, 0.5 to 6 percent of hydroxydecanoic acid, 1 to 10 percent of succinyl glycan and the balance of water or other pharmaceutically / cosmetically acceptable carriers. Wherein the mass ratio of the yeast / zinc fermentation product to the polyaspartic acid chelated zinc is (1: 1)-(8: 1); the mass ratio of the hydroxydecanoic acid to the gluconolactone is (1: 0.5)-(1: 3). The invention provides an efficient, mild and multi-effect synergistic nursing composition, and the composition realizes a three-in-one scalp regulation mechanism of barrier repair, mild bacteriostasis and long-acting moisturizing through unique component synergy.

The invention discloses an amino acid composition for treating alopecia and application of the amino acid composition in preparation of a medicine for treating alopecia, and belongs to the field of medicine configuration products, the amino acid composition is composed of a targeting core intervention component and an auxiliary strengthening synergistic component, the targeting core intervention component is prepared from 30-50 parts of arginine, 50-155 parts of lysine and 50-120 parts of glutamic acid, and the auxiliary strengthening synergistic component is prepared from an auxiliary strengthening synergistic component and an auxiliary strengthening synergistic component. 10 to 40 parts of cysteine and 20 to 60 parts of leucine; the auxiliary strengthening synergistic component is prepared from 15 to 45 parts of tyrosine, 15 to 40 parts of glycine, 10 to 40 parts of glutamine, 20 to 35 parts of serine, 5 to 25 parts of alanine, 2 to 20 parts of aspartic acid and 15 to 35 parts of phenylalanine; the composition can be used as an active ingredient to be prepared into different dosage forms such as a pigmentum, a spray, an ointment and a liniment, is applied to prevention of alopecia and promotion of hair growth, and has a remarkable treatment effect.

The invention provides an olefin polymer composition and application thereof, and relates to the technical field of composite materials. The olefin polymer composition is prepared from the following raw material components in parts by weight: 100 parts of an olefin polymer, 0.5 to 5 parts of an anthraquinone compound and 1 to 5 parts of aspartic ester resin, the structure of the aspartic ester resin contains C8-C24 alkylene and a polyethylene glycol chain segment. The olefin polymer composition has good hydrophilicity, and the treatment effect of the olefin polymer composition on nitrogen-containing sewage can be improved.

The invention belongs to the technical field of agricultural fertilizers, and particularly relates to a cold-resistant feather amino acid leaf fertilizer and a preparation method thereof.The cold-resistant feather amino acid leaf fertilizer is prepared from, by mass, 86%-95% of feather source amino acid-oligopeptide mixed liquor, 3%-8% of L-lysine, 1%-3% of chelated microelements, 0.5%-1.0% of trehalose, 0.5%-1.2% of polyether modified trisiloxane, 0.5%-1.0% of sodium polyaspartate and 0.1%-0.5% of preservative, wherein the pH (Potential of Hydrogen) value is 5.0 to 6.5; the chelated trace elements are EDTA (Ethylene Diamine Tetraacetic Acid) or amino acid chelates of at least three elements of zinc, iron, manganese, copper and boron. By optimizing a feather pretreatment process and a multi-enzyme synergistic system design and combining functional component compounding, the hydrolysis efficiency and the product activity are remarkably improved, and meanwhile, the permeability and the nutrient transfer effect of the foliar fertilizer under a low-temperature condition are enhanced.

A method for preparing a composite nanofiltration membrane based on aspartic acid modified carbon quantum dots belongs to the field of nanofiltration membrane preparation, and comprises the following steps: 1) dissolving citric acid monohydrate in water, adding aspartic acid, heating and stirring, and then adding a sodium hydroxide solution to adjust pH; (2) carrying out suction filtration on the mixed solution obtained in the step (1) by using a microfiltration membrane, dialyzing and purifying in ultrapure water, and freeze-drying to obtain the aspartic acid modified carbon quantum dots; (3) fixing a polysulfone base membrane in a mold, preparing a water-phase solution containing anhydrous piperazine and aspartic acid modified carbon quantum dots, pouring the water-phase solution into the mold to be in contact with the base membrane, and air-drying; and 4) preparing a trimesoyl chloride solution by using n-hexane as a solvent, pouring the trimesoyl chloride solution into a mold for contact, and finally drying to obtain the composite nanofiltration membrane.When the concentration of the aspartic acid modified carbon quantum dots is 2000ppm, the water flux reaches 168LMH, the retention rate reaches a peak value when the concentration of the quantum dots is 1000ppm and is 1.3 times of that of a base membrane, and the composite nanofiltration membrane shows excellent performance.

The invention discloses an engineered glycosyl transferase and application thereof in efficient preparation of triterpenoid saponin. The engineered glycosyl transferase is obtained by mutating serine at the 15th site of UGT74AC1 enzyme into alanine, mutating histidine at the 47th site into aspartic acid, mutating leucine at the 48th site into valine, mutating alanine at the 180th site into serine, mutating histidine at the 180th site into aspartic acid, mutating histidine at the 180th site into aspartic acid, mutating histidine at the 180th site into aspartic acid, mutating histidine at the 180th site into aspartic acid The mutant is obtained by mutating serine at the 332 site into proline, phenylalanine at the 367 site into tryptophan and lysine at the 420 site into arginine. According to the invention, the glycosyl transferase with high catalytic activity is obtained by modifying an enzyme engineering technology, and good application of the glycosyl transferase in synthesis of triterpenoid saponin is realized. The glycosyl transferase disclosed by the invention can also be coupled with sucrose synthase, or coupled with N-acetylhexosamine kinase and N-acetylglucosamine-1-uridine phosphate transferase, and acetylglucosamine is used as a glycosyl donor, so that cascade production of triterpenoid saponin with lower cost and higher efficiency is realized.

The invention relates to the technical field of soil improvement, and particularly discloses a soil conditioner based on microbial community regulation and control and a preparation method thereof, the soil conditioner comprises: (a) a composite functional flora comprising nitrogen-fixing bacteria, phosphate solubilizing bacteria, potassium-dissolving actinomycetes and trichoderma, and the viable count ratio of the nitrogen-fixing bacteria to the phosphate solubilizing bacteria to the potassium-dissolving actinomycetes to the trichoderma is (1.0-1.5): (0.8-1.2): (0.5-1.0): (0.3-0.8); b) modified biochar carrier: the modified biochar carrier is prepared by oxygen-limited thermal cracking of agricultural wastes and is subjected to surface modification by a chitosan solution with a mass fraction of 3-5%; (c) a synergistic component which comprises humic acid particles and an enzymolysis seaweed extract; (d) a flora activator: compounding fructo-oligosaccharide and L-aspartic acid according to a mass ratio of 2: 1; through the synergistic effect of multifunctional composite flora of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, potassium-solubilizing actinomycetes and trichoderma, the biotransformation process of nitrogen, phosphorus and potassium elements in soil is synchronously activated, and the modified charcoal carrier is subjected to multi-stage pyrolysis and chitosan modification to form a graded pore structure.

The invention discloses a circulating water purification treatment process for heat exchange equipment, and relates to the technical field of circulating water purification treatment, and the circulating water purification treatment process comprises the following steps: preparing a polyaspartic acid-silane functionalized grafting intermediate; selecting a porous zeolite matrix, and performing acid activation treatment; the preparation method comprises the following steps: preparing a zeolite matrix, soaking the zeolite matrix in sol, standing, defoaming, heating and calcining to obtain a nano TiO2 coated zeolite matrix of which the surface is coated with nano titanium dioxide; immersing the nano TiO2 coated zeolite matrix into the solution, adjusting the pH value of the solution, and stirring for reaction to obtain a PASP functionalized zeolite filter material; and immersing the PASP functionalized zeolite filter material into a silver nitrate solution, carrying out photocatalytic reduction, and carrying out in-situ reduction and deposition on silver ions to obtain the silver / titanium dioxide-polyaspartic acid synergistic functionalized composite filter material. The composite filter material with synergistic functions realizes efficient scale inhibition and sterilization and rapid purification, shows excellent stability and durability under severe working conditions of high temperature, long period and the like, and is environment-friendly and low in maintenance cost.

In order to improve aggregation property of a PPR protein, the A6 amino acid of the 1st PPR motif from the N-terminus (M1) is made more hydrophilic. Further, the A9 amino acid of M1 is made to be a hydrophilic amino acid or glycine. The A6 amino acid is preferably asparagine or aspartic acid, and the A9 amino acid is preferably glutamine, glutamic acid, lysine, or glycine. Proteins containing such a PPR motif as M1 motif may have not only improved aggregation property, but also high binding power to a target nucleic acid.