752 results about "Aceglatone" patented technology

The invention relates to the technical field of dye synthesis, and particularly discloses a genetically engineered bacterium for synthesizing N-acetyl blue as well as a construction method and application of the genetically engineered bacterium. The supply capacity of precursor substances glutamic acid and glutamine of the genetically engineered bacterium is high, the fermentation process is simple, the production intensity of the precursor substances glutamine and N-acetylglutamine is improved by cutting off a consumption path, relieving negative feedback inhibition and enhancing the expression level of key genes through the genetically engineered bacterium, and finally the yield of N-acetylblue reaches 41.2 g / L.

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

The present application relates to the technical field of biocatalysis and biosynthesis, and specifically discloses a natural blue pigment and a biosynthesis method therefor. The present application uses metabolically engineered bacteria to express indigoidine synthetase and phosphopantetheinyl transferase, to catalyze glutamine and N-acetylglutamine to biosynthesize a natural blue pigment N-acetylindigoidine, and deduces its molecular structure by means of mass spectrometry, nuclear magnetic resonance and other methods. The present application achieves catalytic synthesis of N-acetylindigoidine from glutamine and N-acetylglutamine in Escherichia coli, Corynebacterium glutamicum, Saccharomyces cerevisiae and Streptomyces. Compared with indigoidine, N-acetylindigoidine has a maximum absorption wavelength of 584 nm, possesses better color brightness, and has more stable coloration that is not easily faded, with a very broad application range and industrial production application prospects.

The present application relates to the technical field of biocatalysis and biosynthesis, and specifically discloses a blue pigment and a biosynthesis method thereof. In the present application, an indigoidine synthetase and a 4′-phosphopantetheinyl transferase are expressed by a metabolically engineered strain to catalyze the biosynthesis of the blue pigment N-acetyl-indigoidine from glutamine and N-acetylglutamine, and a molecular structure of the blue pigment is inferred by mass spectrometry, nuclear magnetic resonance spectroscopy, etc. The present application achieves the catalytic synthesis of N-acetyl-indigoidine from glutamine and N-acetylglutamine in Escherichia coli (E. coli), Corynebacterium glutamicum (C. glutamicum), Saccharomyces cerevisiae (S. cerevisiae), and Streptomyces. Compared with indigoidine, N-acetyl-indigoidine has a maximum absorption wavelength of 584 nm, and a stable color having high brightness that is not easy to fade. Thus, the blue pigment shows an extensive application range and a promising industrial production prospect.

The invention discloses a composition for improving the stability of oleuropein in a solution as well as a preparation method and application of the composition. The composition comprises oleuropein and at least one stabilizer, and the stabilizer is selected from the group consisting of anisic acid, lactobionic acid, glycyrrhizic acid, 3, 3-thiodipropionic acid, N-acetyl-L-glutamine, propyl-cysteine and lauramidopropyl betaine; and the pH value of the aqueous solution of the composition is 4.0-8.0. The preparation method comprises the following steps: dissolving oleuropein in water, adding the stabilizer, and uniformly mixing. Through simple physical mixing, by utilizing the synergistic effect of the specific stabilizer and the oleuropein, the degradation and discoloration of the oleuropein in the storage process are remarkably inhibited. Experiments show that after the preferable composition is preserved for 30 days in an open manner, the retention rate of the oleuropein still reaches up to 80% or above, and is far superior to that of blank control and a traditional liposome wrapping method. The composition is simple and convenient in preparation process and low in cost, and provides reliable technical support for wide application of oleuropein in liquid products such as food, medicine and cosmetics.

The invention belongs to the technical field of synthetic biology, and particularly relates to recombinant escherichia coli for efficiently producing O-acetyl-L-homoserine as well as a construction method and application of the recombinant escherichia coli. According to the invention, CRISPR-Cas9 gene editing is combined with metabolic modification, so as to precisely integrate OAH biosynthesis key nodes: introducing and overexpressing a mutant metX gene at a genome pseudogene site to enhance the expression of homoserine acetyltransferase, knocking out byproducts such as poxB and mgsA to synthesize genes, and carrying out high-yield synthesis of OAH. Corynebacterium glutamicum thrA (anti-feedback inhibition), aspB and bacillus subtilis acsA-acuA genes (construction of an acetic acid switch) are introduced, gene expression of gltA, tpiA and the like is optimized to increase supply of precursors such as acetyl CoA and the like, and finally a stable strain without plasmids, antibiotics and inducers is obtained. The production cost is effectively reduced, and the method has the advantage of high genetic stability and shows a good application prospect in OAH industrial production.

The invention relates to the technical field of aquaculture, in particular to a leiocassis longirostris intestinal health functional additive based on spermaceti soxhlet metabolite. The Leiocassis longirostris intestinal health functional additive comprises the following functional components: chondroitin sulfate, N-acetyl-D-galactosamine, 4 ', 4', 4 ', 4', 4 ', 4', 4 ', 4', 4 ', 4', 4 ', 4'- The composition is prepared from the following raw materials: 4, 6-dihydroxyflavone, polydatin, ascorbic acid, glucoside, arabinogalactan, 3-O-beta-D-galactopyranosyl-L-arabinose, tyramine, 4A-hydroxytetrahydrobiopterin, hyaluronic acid and 3-mercapto-2-butanol. According to the technical scheme, the technical problem that an existing probiotic viable bacterium preparation is difficult to meet the intestinal health management requirement in intensive culture of the leiocassis longirostris can be solved. Compared with the prior art, the scheme is more efficient, stable and safe, healthy development of the Leiocassis longirostris breeding industry can be effectively promoted, and the method has ideal application and popularization prospects.

The invention discloses a composition with sensitive skin repairing and anti-aging functions as well as an emulsion and application of the composition, and belongs to the technical field of cosmetics. The composition specifically comprises a pseudoalteromonas fermentation product extract, collagen, palmitoyl tripeptide-5, acetylchitosamine, sodium hyaluronate, silanetriol, caffeine and acetyl hexapeptide-8, and can promote the generation of laminin-5 and integrin beta1, promote the vitality of keratinocytes and fibroblasts, inhibit the growth of the keratinocytes and the fibroblasts, inhibit the growth of the keratinocytes and the fibroblasts, inhibit the growth of the keratinocytes and the fibroblasts, and promote the growth of the keratinocytes and the fibroblasts. The generation of inflammatory factors (IL-6) is inhibited; the generation of collagen IV and collagen VII is promoted; the invention further provides an emulsion prepared from the composition, and the optimal formula of the emulsion is obtained through optimization. The active composition disclosed by the invention has a wide application prospect in the field of cosmetics, and particularly has important significance in sensitive skin repair and anti-aging directions.

The invention relates to a culture medium for high-density serum-free suspension culture of BHK-21 cells and application of the culture medium. The culture medium contains inorganic salt, amino acid, vitamins, energy substances, a buffer substance, an antioxidant, sterol, polyamine, an additive and an indicator, and the antioxidant comprises dihydrolipoic acid and S-acetyl-L-glutathione. According to the invention, the culture medium for serum-free suspension culture of the BHK-21 cells, which is clear in components and remarkable in culture effect, can be provided. The added dihydrolipoic acid and S-acetyl-L-glutathione are combined as antioxidants of the culture medium, so that the survival rate of BHK-21 cells cultured in the culture medium is improved while the oxidation resistance of the serum-free suspension culture medium is improved.

The invention relates to the technical field of functional food, in particular to immune regulation type prebiotic syrup with synergy of galactomannan. The active components of the composite solid beverage are prepared from the following raw materials in percentage by weight: 20%-35% of fructo-oligosaccharide, 10%-18% of galactooligosaccharide, 8%-15% of stachyose, 3%-7% of xylooligosaccharide, 5%-12% of lactitol, 5%-10% of galactomannan, 2%-5% of yeast beta-glucan and 1%-3% of N-acetylglucosamine. The composition further comprises 4-8% of inulin and 3-6% of resistant dextrin as a matrix filling and slow-release carrier, and the sum of the weight percentages of all the active ingredients and the carrier is 100%. By remodeling intestinal microecology and inhibiting inflammation pathways, the intestinal inflammation state can be remarkably improved, expression of intestinal mucosa tight junction protein is promoted, and an innovative solution is provided for people suffering from chronic bowel diseases and immune imbalance.

The invention provides an L-arginine production strain and a construction method and application thereof, corynebacterium glutamicum AJC is modified by a metabolic engineering method to obtain the L-arginine production strain, the synthesis path of arginine is optimized, and a carbon source efficiently flows to arginine by means of promoter replacement, multi-copy and the like; by introducing an exogenous gene pyrABE949 *, the supply of a precursor substance carbamyl phosphate is enhanced; by introducing an exogenous gene pntAB, a new direction is provided for supply of coenzyme NADPH, and a large amount of reducing power is provided for synthesis of arginine; an exogenous gene fxpk is introduced, an NOG system is constructed, an acetyl coenzyme A pool is enriched, a large number of acetyl coenzyme A precursors are provided, and the engineering bacterium has the characteristics of high yield and stability and has good industrial application value in the aspect of fermentation production of L-arginine.

The invention provides a cordyceps militaris mycelium and a preparation method and application thereof, and relates to the technical field of biological materials. According to the invention, chitinase is added into the cordyceps militaris mycelium material to carry out enzymolysis on chitin to obtain chitooligosaccharide and N-acetylglucosamine, so that beta-glucan in a mycelium framework is dissolved out, and the grafting efficiency of the cordyceps militaris mycelium material is improved; furthermore, the antibacterial effect of the antibacterial material is improved by carrying out grafting reaction on the cordyceps militaris mycelium material and an exogenous monomer antibacterial peptide which has antibacterial performance and contains carboxyl groups.

The invention relates to the technical field of chemical intermediates, and particularly discloses a preparation method of a givelastat intermediate.According to the preparation method, an initiator compound 5 can be synthesized by adopting cheap 2-hydroxy-6-naphthoic acid (CAS: 16712-64-4, 141 yuan / kg), and the preparation method is different from a method in the prior art. A gemvelastat intermediate compound 4 is synthesized from a compound 5 through a three-step reaction, compared with the prior art, the yield is high, industrial amplification production is more facilitated, in the process of synthesizing a compound 6 from the compound 5, acetonitrile can be adopted as a cyanide source in a reaction system, activated hydroxyl is subjected to a coupling reaction, and the yield is high. In the process of synthesizing a compound 6 from a compound 7 instead of a traditional metal cyanide, or in the process of synthesizing a compound 6 from another compound 5, a cheap cuprous cyanide and cuprous iodide system is adopted for a coupling reaction, and in the process of synthesizing a compound 4 from a compound 7, an acetic acid and sodium triacetoxyborohydride reaction system is adopted, so that the compound 6 is synthesized. And the important intermediate of the givelastat can be obtained with high yield.

The invention relates to a method for producing 6 '-fucosylated chitosan disaccharide GlcNacbeta1-4 (Fucalpha1-6) GlcNAc through double-bacterium coupling fermentation, and belongs to the technical field of fermentation engineering. The method comprises the following steps: taking fucose and N-acetyl-D-glucosamine as substrates in a fermentation system; the 6 '-fucosylated chitosan disaccharide is produced through coupled fermentation of an engineering escherichia coli strain and yeast, and a GlcNAcbeta1-4 (Fucalpha1-6) GlcNAc synthesis pathway including N-acetylhexosamine 1-kinase nahK, fucosyltransferase nodZ, L-fucose kinase Fkp and N, N-diacetylchitosan phosphorylase Chbp is constructed in the engineering escherichia coli, so that the 6'-fucosylated chitosan disaccharide is obtained. According to the invention, the yeast is added to realize cyclic regeneration from GMP to GTP, so that not only is the problem of high oligosaccharide production cost caused by pure exogenous supplement of GTP effectively solved, but also efficient production of GlcNAcbeta1-4 (Fucalpha1-6) GlcNAc is realized, and the yield of GlcNAcbeta1-4 (Fucalpha1-6) GlcNAc is increased to 25.50 g / L by an optimized coupling fermentation production technology. The invention provides a novel synthesis technology of complex N-glycans, and has a wide application prospect.

The invention relates to an N-acetyl-D-glucosamine composition with an anti-tumor effect and application of the N-acetyl-D-glucosamine composition, and relates to the technical field of medicines and health care products, the N-acetyl-D-glucosamine composition with the anti-tumor effect comprises the following raw materials by weight: 17-29 parts of N-acetyl-D-glucosamine and 5-10 parts of an extract of Tongshan. According to the invention, the N-acetyl-D-glucosamine and the extract in a proper proportion are matched for use for the first time, so that the synergistic interaction of the N-acetyl-D-glucosamine and the extract is realized. In-vitro animal anti-tumor experiments show that the N-acetyl-D-glucosamine composition provided by the invention can significantly reduce the tumor volume in a rat model, provides a new way for clinical treatment of tumor patients, and has a wide application prospect.

The present invention discloses a lactoferrin composition and its application for improving immunity by regulating macrophage immune activity, and belongs to the technical field of functional compositions. The present invention obtains a lactoferrin composition with regulating macrophage immune activity by compounding lactoferrin, α-lactalbumin, N-acetylneuraminic acid and yeast β-glucan in a specific ratio, the raw material of the composition is easy to obtain, and four components work together to significantly enhance its phagocytic activity without changing the activity of macrophages, regulate the polarization state of macrophages in inflammatory response, inhibit macrophages from polarizing to pro-inflammatory M1 type, and promote macrophages to polarize to anti-inflammatory M2 type; At the same time, the composition can also enhance the antigen presentation ability of macrophages and the activation of immune T cells, and improve body immunity. Therefore, the composition provided by the present invention can be used to prepare health products, food or medicines, etc. that improve immunity.

The invention discloses a culture medium of a lacrimal gland organ and a culture method of the lacrimal gland organ, and the culture medium of the lacrimal gland organ is composed of a basic culture medium, R-spodin3, Noggin, B27, N-acetyl-L-cysteine, trehalose, vitamin C, glutathione, an adenylate cyclase activator, A8301, PGE2 and FGF10. The culture medium for lacrimal gland organ culture, provided by the invention, is prepared from various cell factor components according to an optimized proportion, and is simple and reasonable in components and rich in nutrition; when the culture medium is used for culturing the lacrimal gland organoid, the formation and growth of the organoid can be promoted, an in-vivo complex microenvironment is further simulated, the organoid is closer to an in-vivo physiological state, an organoid model is better constructed so as to evaluate the influence of drugs on lacrimal gland functions, and a new platform is provided for drug screening; and a new way is opened up for follow-up treatment of diseases such as xerophthalmia in the future.

The invention relates to the field of biological medicines, and discloses application of N-acetylglutamic acid in preparation of anti-myocardial fibrosis medicines. According to the application disclosed by the invention, the N-acetylglutamic acid and the carglutamic acid are found to have the effects of obviously improving the systolic function of the heart, reducing the energy metabolism deposition of the fibroblasts and reducing the collagen deposition so as to inhibit excessive fibrosis of the myocardial fibroblasts after myocardial infarction for the first time. The discovery provides a'switch 'for fibroblast repair of myocardial infarction and excessive fibrosis, and has important value for avoiding the excessive fibrosis of the heart after myocardial infarction.

The disclosure provides methods for synthesis of peracetylgalactosamine-1-pentanoic acid, also called peracetylated D-galactosamine C5 linker or GalNAc C5 linker, using a vegetal source as a starting material, such as vegetal-sourced D-glucosamine or D-glucosamine hydrochloride. Also provided are methods for purifying the peracetylgalactosamine-1-pentanoic acid, or GalNAc C5 linker, thus produced so that the end product comprises fewer impurities.

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 discloses an application of a composition of L-arginine and L-histidine in improving the yield of N-acetylglucosamine produced by microbial fermentation. The invention also discloses a culture medium for fermentation production of N-acetylglucosamine. The culture medium comprises a basic culture medium and a fed-batch culture medium, wherein the fed culture medium is prepared from the following components: 600 to 800 g / L of glucose, 4 to 6 g / L of monopotassium phosphate, 80 to 120 g / L of glycerol, 0.8 to 1.5 g / L of L-arginine and 0.8 to 1.5 g / L of L-histidine. According to the method, L-arginine and L-histidine with specific concentrations are added in the microbial fermentation process for producing N-acetylglucosamine, so that the yield of N-acetylglucosamine can be remarkably increased.

The invention discloses a synthesis method of helicid, and relates to the technical field of compound synthesis, glucose is taken as an initial raw material, allose is obtained through a series of reactions, pentaacetyl allose is prepared from allose through acetylation reaction, tetraacetyl alloside is prepared through selective deacetylation reaction, substitution reaction and nucleophilic substitution reaction, and the helicid is synthesized through a one-step method. And finally, carrying out a deacetylation reaction on the tetraacetyl alloside to prepare helicid. Helicid has the effects of calming, sleeping, easing pain and resisting inflammation, and can be applied to preparation of medicaments with corresponding effects. The preparation method of the helicid provided by the invention is simple to operate, can be used for large-scale industrial production, and overcomes the defect of insufficient yield of naturally extracted helicid.

The invention belongs to the technical field of cosmetics, particularly discloses moisturizing nano-liposome emulsion prepared by a microjet method and a preparation method of the moisturizing nano-liposome emulsion, and aims to solve the problems of poor stability of active ingredients, low transdermal absorption efficiency, single effect and non-uniform particle size in a liposome preparation process in the existing moisturizing cosmetics. The nano-liposome emulsion is prepared from glycosylglycerol, acetylchitosamine, tremella polysaccharide, a myrothamnus flabellifolia leaf / stem extract, an artemisia annua extract, a lactobacillus fermentation product, flat nuclear wood oil, hydrogenated lecithin and phosphatidylcholine. The emulsion has excellent moisturizing, soothing and repairing effects, can be used for preparing skin care products such as water aqua, emulsion and cream, and has the advantages of high utilization rate of active ingredients and good stability.

The invention discloses an N-acetylglucosamine transferase AcetRS-K23G and an application thereof, and belongs to the technical field of functional enzymes. And the amino acid sequence of the N-acetylglucosamine transferase AcetRS-K23G is as shown in SEQ ID NO. 3. The invention further discloses an application of the N-acetylglucosamine transferase AcetRS-K23G in the preparation of the chitosan oligosaccharide. The N-acetylglucosamine transferase AcetRS-K23G disclosed by the invention is obtained by performing mutation modification on the N-acetylglucosamine transferase AcetRS, and can be used for producing the chitosan oligosaccharide with the polymerization degree of 5-7, especially the heptaose, the yield of the heptaose can reach 42.01 mg / L, and the N-acetylglucosamine transferase AcetRS-K23G is an ideal functional enzyme for industrially producing the heptaose. The product spectrum of the N-acetylglucosamine transferase is widened, and the N-acetylglucosamine transferase can be used for preparing high-polymerization-degree chitosan oligosaccharide and has a wide application prospect.

The present invention relates to antibody conjugates which are particularly suitable for targeting cells expressing PTK7, in particular tumor cells. An antibody conjugate according to the present invention has structure (1): AB-[(L6) b-{Z-L-D} x] y (1) wherein AB is an antibody capable of targeting a tumor expressing PTK7; l is a joint connecting Z to D; z is a linking group; l6 is-GlcNAc (Fuc) w-(G) j-S-(L7) w '-wherein G is a monosaccharide, j is an integer in the range of 0 to 10, S is a sugar or a sugar derivative, GlcNAc is N-acetylglucosamine, and Fuc is fucose, w is 0 or 1, w' is 0, 1 or 2, and L7 is-N (H) C (O) CH2-,-N (H) C (O) CF2-or-CH2-; d is selected from the group consisting of an anthracycline, a camptothecin, a tubulysin, an endiyne, an amanitine, a duocarmycin, a maytansinoid, an aurestatin, eribulin, a BCL-XL inhibitor, a miscanthus semiaquilaria, a KSP inhibitor, a TLR agonist, an indolo-benzodiazepine dimer or a pyrrolo-benzodiazepine dimer (PBD), and an analog or prodrug thereof; b is 0 or 1; x is 1 or 2; and y is 1, 2, 3 or 4. The invention further relates to a method for preparing said antibody conjugate of structure (1) and to the use of said antibody conjugate of structure (1).

The invention relates to a gastric acid-resistant sustained-release intestinal bacteria capsule based on bionic mucous membrane-enzymolysis response and a preparation method thereof. The gastric acid-resistant sustained-release intestinal bacteria capsule comprises a core layer, an adhesive layer, an outer-layer composite film and a protective coating from inside to outside, the core layer consists of intestinal flora and a multifunctional freeze-drying protective agent; the adhesive layer is composed of trehalose, N-acetyl glucosamine and MUC2 recombinant protein; the outer-layer composite film is composed of a base material and a functional filler; the protective coating is composed of beewax and chitosan. The anti-gastric acid sustained-release intestinal bacteria capsule based on bionic mucosa-enzymolysis response provided by the invention has excellent gastric acid resistance, and the gastric acid resistance is remarkably improved; good slow release performance is achieved, and accurate slow release of enzymatic hydrolysis response can be achieved; the colonization efficiency of the intestinal bacteria can be effectively improved; the storage stability is good. The preparation method provided by the invention has the advantages of simplified steps, short time consumption, controllable core operation time and obviously shortened whole process, and is beneficial to keeping the activity of the flora.

The invention relates to the field of anti-allergic compositions, and discloses an immunoregulation anti-allergic compound powder based on non-active yeast and probiotics, and the immunoregulation anti-allergic compound powder comprises the following components in parts by mass: 15-30 parts of non-active yeast powder, 10-25 parts of a probiotic composition, 40-55 parts of a prebiotic composition, 4-6 parts of fucoidin, 0.5-1.5 parts of N-acetylneuraminic acid, and 5-10 parts of an auxiliary material; wherein the prebiotic composition is prepared from resistant dextrin, stachyose, fructo-oligosaccharide and galactooligosaccharide; the auxiliary materials comprise at least two of anhydrous dextrose, acerola cherry powder, elderberry powder, sorbitol and yeast beta-glucan. Through the coupling design of low-temperature mixing and a step-by-step embedding process, the mobility of the powder is maintained, and meanwhile, the activity of thermosensitive components is kept. Compared with a conventional high-temperature mixing or disordered adding process, the problems of component damage and function loss caused by a heat effect or mechanical shearing are solved.

The invention relates to the technical field of medicines, and provides sea sodium polysaccharide, a preparation method and application thereof, and an anticoagulant and / or antithrombotic drug of a targeted endogenous coagulation pathway. The sea sodium polysaccharide provided by the invention is fucosylated chondroitin sulfate polysaccharide, the weight-average molecular weight is 90000-130000, the molar ratio of glucuronic acid to N-acetylgalactosamine to fucose is 1: (0.8-1.2): (0.5-0.8), and the mass percentage of sulfate group is 25-40%. The sea sodium polysaccharide provided by the invention can act on a terminal rate-limiting enzyme (iFXase) in an endogenous blood coagulation pathway in a targeting manner, is not obvious in effect on blood coagulation factors in other blood coagulation pathways, realizes the effects of anticoagulation and no bleeding, can be widely applied to acute-stage and recovery-stage treatment of cerebral arterial thrombosis, and has a wide application prospect. The problem of safety of anticoagulant and antithrombotic drugs used by clinical cerebral arterial thrombosis patients is solved, and a new field of research and development of targeted endogenous coagulation pathway rate-limiting enzyme anticoagulant drugs is developed.

The invention discloses a CgGlmS mutant and application of the CgGlmS mutant in synthesis of N-acetylglucosamine (GlcNAc) from corynebacterium glutamicum, and belongs to the technical field of biology. According to the invention, a bottleneck enzyme CgGlmS in a synthetic route of N-acetylglucosamine is subjected to deep rational analysis and semi-rational transformation. Through systematic research on the structure and function of an original CgGlmS enzyme from corynebacterium glutamicum S9114, the efficient CgGlmS mutant A253M is successfully screened out, and the enzyme activity, stability and catalytic efficiency of the mutant are obviously improved compared with those of a wild type. The mutant CgGlmS is overexpressed in corynebacterium glutamicum S9114 by using plasmids, so that the yield of N-acetylglucosamine in corynebacterium glutamicum is increased. The CgGlmS enzyme is directionally modified, so that the catalytic efficiency of the CgGlmS enzyme is improved, accumulation of N-acetylglucosamine in corynebacterium glutamicum is further promoted, and powerful support is provided for efficient production of the corynebacterium glutamicum.

The invention discloses a construction method of recombinant corynebacterium glutamicum for fermentation synthesis of poly beta-(1, 6)-N-acetylglucosamine polysaccharide, and belongs to the technical field of bioengineering. The recombinant corynebacterium glutamicum capable of preparing the PNAG through fermentation is constructed by using synthetic biology and genetic engineering technologies for the first time, cheap carbon sources and nitrogen sources can be utilized, the recombinant corynebacterium glutamicum is suitable for high-density fed-batch fermentation, and the generation cost of the PNAG is reduced; the yield after 42 hours of fermentation can reach 6.82 g / L, and the method has industrial application potential.