26 results about "Polysaccharide synthesis" patented technology

Provided are an Aeromonas dhakensis mutant strain with deletion of a surface polysaccharide synthesis gene, a complemented strain, a construction method therefor, and the use thereof. The mutant strain is obtained by deleting one or more of ugd, ugd2, and cap1J from the Aeromonas dhakensis wild strain A. dhakensis C160501.

The invention belongs to the technical field of biomedical treatment and biological fermentation, discloses a metagen composition for effectively inhibiting oral dental caries and application thereof, and aims to solve the problems of great side effect, weak effect and unknown mechanism of the existing dental caries prevention and treatment means. The composition is prepared by mixing a metagen 1 which is prepared by fermenting lactobacillus salivarius Postbio-YY with a metagen 2 which is prepared by fermenting lactococcus lactis Postbio-F3 and lactobacillus paracasei Postbio-P6 step by step. In the preparation process, the active ingredients are reserved by accurately controlling the fermentation pH, time and pasteurization parameters. The composition can be prepared into multiple dosage forms such as toothpaste and the like, can remarkably inhibit the growth of streptococcus mutans and destroy the thallus structure, inhibits biofilm and exopolysaccharide synthesis by down-regulating fimI, wcaJ and wcae genes, is safe and free of side effects, and provides an efficient scheme for decayed tooth prevention and treatment.

The invention discloses a method for efficiently preparing high-activity hericium erinaceus polysaccharide from waste in the edible mushroom industry, and belongs to the technical field of deep processing of edible mushrooms and recycling of waste. The method comprises the following steps: carrying out steam explosion pretreatment on hericium erinaceus waste mushroom residues, and carrying out synergistic compatibility on the hericium erinaceus waste mushroom residues, tea residues, bean residues and citrus residues which are subjected to specific enzymolysis to prepare a liquid fermentation culture medium; a two-stage control strategy is adopted for submerged fermentation of hericium erinaceus liquid, and hypha proliferation and polysaccharide synthesis conditions are optimized; and after fermentation is finished, extracting and purifying mycelium polysaccharide by adopting a choline chloride-lactic acid eutectic solvent system. According to the method, high-valued utilization of the edible fungus chaff and various agricultural byproducts is achieved, the content of beta-(1-> 3)-D-glucan in the prepared hericium erinaceus polysaccharide is larger than or equal to 55%, the immunocompetence (IC50) reaches 32 micrograms / mL, the hericium erinaceus polysaccharide is remarkably superior to commercially available products, and the hericium erinaceus polysaccharide can be directly used as functional food and medicine raw materials. The process is green and efficient, and has remarkable economic and environmental benefits.

The invention provides a high-lubrication and high-adhesion hydrogel material based on enzymatic in-situ forming as well as a preparation method and application of the high-lubrication and high-adhesion hydrogel material. The high-lubricity hydrogel is composed of lipid nanoparticles, natural polysaccharide / synthetic polymer monomers and cascade enzymes, and is prepared by catalytically oxidizing polysaccharide through the cascade enzymes and then forming Schiff base crosslinking with aminated monomers. Dynamic covalent bonds and lipid nanoparticles are introduced to endow the hydrogel with dynamic super lubrication and static high adhesion performance, and meanwhile, energy dissipation is realized through dynamic bond breakage and recombination to provide a damping effect, so that mechanical damage to a moving part is reduced; in addition, the cascade enzyme participates in metabolism regulation and control of complex microenvironment of the movement part, and the loaded nucleic acid intervenes in a disease treatment target at a deep gene level to synergistically remodel a healthy ecological niche of the movement part.

The invention belongs to the technical field of microorganisms, and particularly relates to rhizoma polygonati endophytic bacillus cereus and application thereof. The rhizoma polygonati endophytic bacillus cereus SK6 is separated and screened from rhizoma polygonati, the bacillus cereus is preserved in the China General Microbiological Culture Collection Center, and the preservation number is CGMCC (China General Microbiological Culture Collection Center) No.36060. The bacillus cereus strain provided by the invention has excellent exopolysaccharide synthesis capability, and the exopolysaccharide content in the fermentation liquor obtained by fermenting the bacillus cereus at 37 DEG C for 24 hours is up to 44.22 g / L.

The invention discloses a dendrobe small RNA (Ribonucleic Acid) miR421 and an application thereof. According to the application of the miR421 in regulation and control of synthesis of the plant polysaccharide, the mature sequence of the miR421 is as shown in SEQ ID NO. 1. According to the invention, miR421 belonging to dendrobium is cloned from dendrobium officinale leaves, the miR421 is used as a negative regulatory factor to participate in regulating the synthesis process of dendrobium polysaccharide, and transient expression and functional identification prove that the polysaccharide content of transgenic dendrobium is reduced when the miR421 is excessively expressed. Therefore, the miR421 has important theoretical guidance significance and application value in the fields of synthesis of secondary metabolites of orchid plants and medical application.

The present invention relates to device for automated synthesis of oligo- and polysaccharides on a solid support.

This invention discloses an engineered strain of Streptococcus suis Δ07335-hSLY (classification name: Streptococcus suis Δ07335-hSLY, deposit date: May 13, 2026, deposit number: CCTCC NO: M2026937), its construction method, and applications, relating to the fields of microbial genetic engineering and drug screening technology. This invention uses Streptococcus suis SC19 strain as the starting strain and obtains the engineered strain SC19Δ07335 by knocking out the 07335 gene in its genome using homologous recombination technology. Compared with the starting strain SC19, the expression level of the hemolysin SLY gene in this engineered strain is significantly upregulated, increasing the success rate of the hemolysis test in the culture supernatant from 30% to 100%. Simultaneously, the expression of the capsular polysaccharide synthesis gene CPS is downregulated, the capsule becomes thinner, and the in vivo virulence is significantly reduced. The anti-hemolytic active compound screening system established based on this engineered strain is stable and reliable, and compounds with anti-SLY activity, such as baicalin, have been successfully screened. Animal experiments have verified that the survival rate of mice in the medium and high dose treatment groups of baicalin reached 100%.

The invention discloses klebsiella pneumoniae based on CRISPR (clustered regularly interspaced short palindromic repeats) / cas12a and detection of an ethanol dehydrogenase gene of the klebsiella pneumoniae. The invention provides a kit for detecting klebsiella pneumoniae and an ethanol dehydrogenase gene thereof. The kit comprises the following components: 1) a primer group for amplifying a gene rcsA; 2) a primer group for amplifying the gene adh; 3) a Cas12a protein, a crRNA combined with a gene rcsA and a crRNA combined with a gene adh; a specific and conservative capsular polysaccharide synthesis regulatory factor rcsA is selected as a target sequence for identifying klebsiella pneumoniae, and an ethanol dehydrogenase gene adh is selected as a target sequence for identifying ethanol production. Meanwhile, the detection conditions of the platform are optimized, and the sensitivity and specificity of the platform are determined. The invention develops a double-target detection kit based on CRISPR / Cas12a, and realizes high-sensitivity and high-specificity rapid identification of klebsiella pneumoniae and ethanol production capacity thereof by simultaneously targeting rcsA gene and adh gene.

The application discloses application of amino peptidase SapM in regulating virulence and motility of Xanthomonas campestris, and belongs to the technical field of biotechnology.The sapM gene function is researched by constructing a sapM gene deletion strain of Xanthomonas campestris.The research finds that knocking out the sapM gene (Delta sapM) significantly enhances the pathogenicity, extracellular polysaccharide (EPS) synthesis, amylase activity and motility of Xcc, while sapM overexpression inhibits the above-mentioned phenotypes.The flagellum morphology of the sapM mutant strain is further observed by transmission electron microscopy, and it is found that the flagellum length of the sapM mutant strain is significantly different from that of the wild type.It can be seen that the amino peptidase SapM is involved in negative regulation of virulence and motility of Xanthomonas campestris, and the application has great application value.

The invention belongs to the technical field of fermentation, and particularly relates to a method for inducing generation of water-soluble pachymaran. According to the method, Wolfiporia cocos and Trichoderma longibrachiatum are subjected to staged co-culture, and low-temperature stress at the temperature of 15 DEG C is applied to the key stage of co-culture. The specific strain combination and low-temperature induction have a synergistic effect, so that a water-soluble polysaccharide synthesis and secretion pathway of the poria cocos bacteria is remarkably activated, and the technical bottlenecks of low water-soluble polysaccharide proportion and low yield in the existing fermentation process are solved. The yield of the prepared water-soluble pachymaran can reach 2.35 g / L, the immunoregulatory activity of the water-soluble pachymaran is excellent, macrophages can be effectively promoted to secrete key cell factors such as IL-6 and IL-1beta, and a new technical scheme is provided for developing efficient and high-value pachymaran products.

The invention discloses construction and application of a vibrio parahaemolyticus capsular polysaccharide synthesis gene cluster and lipopolysaccharide synthesis HldE mutant strain, and belongs to the technical field of molecular biology and genetic engineering.According to the construction method, an overlapping extension PCR technology is adopted for constructing a kanamycin resistance gene knockout fusion fragment, the fusion fragment is cloned into a suicide plasmid pDS132, and the suicide plasmid pDS132 is used for preparing the HldE mutant strain of the vibrio parahaemolyticus capsular polysaccharide synthesis gene cluster and lipopolysaccharide synthesis HldE mutant strain. A recombinant suicide plasmid is introduced into vibrio parahaemolyticus through conjugational transfer, and sucrose-induced double-exchange homologous recombination and kanamycin resistance screening are utilized to efficiently obtain a capsular polysaccharide synthetic gene cluster and an HldE gene knockout mutant strain. The invention further discloses an application of the mutant strain in evaluating the exposure of the outer membrane protein, and discloses the influence of a capsule and a lipopolysaccharide layer on the accessibility of an outer membrane protein antibody. The method is easy and convenient to operate and high in screening efficiency, and an effective tool is provided for vibrio outer membrane protein function research, vaccine target screening and pathogenic mechanism analysis.

This invention discloses the application of L-tryptophan in the preparation of anti-caries oral care products, belonging to the field of biomedical technology. Addressing the safety issues, oral microecological disruption, and susceptibility to drug resistance associated with existing anti-caries agents (such as fluoride and chlorhexidine), this invention proposes using L-tryptophan as the effective active ingredient in anti-caries agents. Utilizing the specific effects of L-tryptophan on *Streptococcus mutans*, it achieves the effects of inhibiting tooth decay, maintaining oral microecological balance, and reducing the risk of bacterial drug resistance. This specific effect, without affecting the survival of *Streptococcus mutans*, simultaneously inhibits the synthesis of water-insoluble extracellular polysaccharides, inhibits acid production and acid tolerance, and inhibits oxygen tolerance and interspecies competition. It is characterized by its clear efficacy and high safety.

Viscosity-resistant Corynebacterium glutamicum and a use thereof, relating to the technical field of biological genetic engineering. The Corynebacterium glutamicum is obtained by mutating Corynebacterium glutamicum ATCC 13032. Mutation sites include: cytosine mutation to thymine at the position 862902; guanine mutation to adenine at the position 862903; cytosine mutation to thymine at the position 862953; adenine mutation to guanine at the position 862961; cytosine and thymine insertion at the position 862958; and guanine deletion mutation at the position 862963. The tolerance of the Corynebacterium glutamicum in a highly viscous environment and the growth and metabolism ability of the Corynebacterium glutamicum in a low dissolved oxygen environment are significantly improved, thereby improving the yield of a mucopolysaccharide and avoiding the problem of the mucopolysaccharide synthesis being affected by restricted metabolism of the Corynebacterium glutamicum due to a viscous fermentation broth and insufficient dissolved oxygen resulting from the generated mucopolysaccharide.

Provided is a method for constructing a recombineered strain with a low level of endotoxin and a high yield of colanic acid, comprising: (a) constructing a colanic acid synthesis strain from a starting strain, and (b) genetically engineering, on the basis the colanic acid synthesis strain, an endotoxin synthesis pathway, wherein the recombineered strain of colanic acid comprises: a) a lipopolysaccharide core polysaccharide synthesis gene cluster comprising waaL, waaU, waaZ, waaY, waaR, waaO, waaB, waaP, waaG, and waaQ on the genome being knocked out or downregulated, and the Lon protein-encoding gene lon and the HNS regulatory protein-encoding gene hns being knocked out or downregulated, b) the Vitreoscilla hemoglobin VHb being overexpressed, and c) the lpxP gene being knocked out or downregulated.

The invention discloses an OMV vaccine capable of preventing group B streptococcus III serotype infection and a preparation method thereof. The invention belongs to the field of synthetic biology, and particularly relates to an OMV vaccine capable of preventing group B streptococcus III serotype infection and a preparation method of the OMV vaccine. The recombinant escherichia coli contains a lipoid A deacylase coding gene, a lipoid A dephosphatase coding gene and a group B streptococcus capsular polysaccharide length control gene coding gene; the gene does not contain an acetyl glucosamine phosphotransferase coding gene, an escherichia coli O antigen synthesis gene cluster coding gene, a lipoid A myristoyl transferase coding gene, an escherichia coli O antigen chain length control gene coding gene, a lipoid A palmitoyl transferase coding gene and an escherichia coli sialic acid degradation gene cluster coding gene. The composition also contains a group B streptococcus III capsular polysaccharide synthesis cluster coding gene. The recombinant escherichia coli can be used for producing an OMV vaccine for preventing group B streptococcus III serotype infection.

The invention belongs to the technical field of microbial fermentation, and relates to a method for increasing the yield of lactobacillus rhamnosus exopolysaccharides. The method provided by the invention comprises the following steps: inoculating activated lactobacillus rhamnosus into an improved MRS liquid culture medium containing 0.1 to 0.4 M of sodium lactate, and carrying out standing culture, so as to obtain the fermentation liquor. According to the method, the synthesis of the exopolysaccharide is obviously promoted under the conditions of not changing the existing fermentation process and not increasing complex steps. Meanwhile, the neutral polysaccharide EPS-0 and the acidic polysaccharide EPS-1 extracted from the fermentation liquor obtained by the method have antioxidant activity, and can be directly used as natural antioxidants for functional food, cosmetics or medical intermediates. The method is simple in process, low in cost and easy to amplify, and a new technical path is provided for large-scale production and high-end application of the lactobacillus rhamnosus exopolysaccharide.

The invention relates to the field of bioengineering and polysaccharide synthesis, and discloses a haemophilus influenzae type b polysaccharide synthesis method which comprises the following steps: carrying out phosphorylation polymerization reaction on ribose and a ribitol phosphate monomer in a liquid phase reaction system to obtain a primary reaction solution, and adding a polarity regulator until the light transmittance of the system reaches a metastable state threshold value; carrying out variable-temperature phase annealing treatment on the system in a metastable state threshold value, alternately carrying out swelling diffusion and dense rearrangement operation, reducing entanglement density by utilizing a solvation effect, and removing non-crystalline impurities by utilizing a supersaturation degree difference; according to the method disclosed by the invention, the variable-temperature phase annealing treatment is utilized, an in-situ grading purification field is constructed by periodically adjusting system solubility parameters, and high-efficiency purification and lattice regularization of high-molecular-weight polysaccharide long chains are realized under the condition of not needing a chromatography medium; the purity and the structural orderliness of the product are improved.

The invention provides a method for preparing cationic tremella polysaccharide through fermentation-chemical cascade and application of the method, and belongs to the technical field of biological material preparation.The method mainly comprises the steps that alkali liquor is added into tremella polysaccharide fermentation liquor, the temperature is increased and maintained for a period of time, tremella polysaccharide fermentation breaking liquor is obtained, then a cationization reagent solution is added, and the cationic tremella polysaccharide fermentation breaking liquor is obtained; reacting for a period of time to obtain a cationic tremella polysaccharide reaction solution, and performing pH adjustment, coarse filtration, alcohol precipitation, redissolution, fine filtration, secondary alcohol precipitation, dehydration and drying to obtain the cationic tremella polysaccharide. According to the method, the step of secondary refining is omitted, the synthesis time of the cationic tremella polysaccharide is remarkably shortened, repeated operation is avoided, the production cost of a factory is reduced, and the prepared cationic tremella polysaccharide has a better moisture retention effect and repairing capacity on damaged hair.

Provided is a method for constructing a recombineered strain with a low level of endotoxin and a high yield of colanic acid, comprising: (a) constructing a colanic acid synthesis strain from a starting strain, and (b) genetically engineering, on the basis the colanic acid synthesis strain, an endotoxin synthesis pathway, wherein the recombineered strain of colanic acid comprises: a) a lipopolysaccharide core polysaccharide synthesis gene cluster comprising waaL, waaU, waaZ, waaY, waaR, waaO, waaB, waaP, waaG, and waaQ on the genome being knocked out or downregulated, and the Lon protein-encoding gene lon and the HNS regulatory protein-encoding gene hns being knocked out or downregulated, b) the Vitreoscilla hemoglobin VHb being overexpressed, and c) the lpxP gene being knocked out or downregulated.

The invention discloses a dendrobium officinale forest medicine mode cultivation effect evaluation method and system, and relates to the technical field of ecological cultivation, and the method comprises the steps: predicting a time-delay response coefficient of temperature and humidity fluctuation to a polysaccharide synthesis rate through a medicine effect component accumulation model based on a matrix-moisture cooperative regulation record and a standardized root activity value; obtaining a pesticide effect regulation and control digital instruction; executing the pharmacodynamic regulation and control digital instruction, obtaining pharmacodynamic component measured data, calculating a polysaccharide content standard-reaching rate, and obtaining a carbon balance index and a pharmacodynamic stability coefficient in combination with a photosynthetic carbon sequestration amount and a production link carbon emission amount; and based on the carbon balance index and the pesticide effect stability coefficient, simulating ecological adaptability and pesticide effect component stability under different binding and planting densities and attachment tree species combinations through a digital twinborn model, and generating a cultivation effect evaluation report. According to the method, non-linear coupling evaluation of ecological benefits and drug effect stability is realized, and the accuracy and predictive ability of evaluation of the cultivation effect of the dendrobium officinale forest drug mode are improved.

The invention discloses an Aspergillus scheffleri strain and application thereof, the strain is named as Aspergillus scheffleri LH-03, the preservation number is CGMCC (China General Microbiological Culture Collection Center) NO.41987, the preservation date is May 7, 2025, and the preservation unit is China General Microbiological Culture Collection Center. The strain shows efficient exopolysaccharide synthesis capability, and the yield of the synthesized exopolysaccharide is obviously higher than that of a conventional production strain.

The invention discloses a phellinus igniarius polysaccharide synthesis system based on a carbon metabolic flow optimal distribution mechanism. A liquid culture medium of the phellinus igniarius polysaccharide synthesis system comprises the following ingredients: glucose, corn flour, wheat bran powder, peptone, dipotassium phosphate, magnesium sulfate and vitamin B2; all the components are mixed with water to obtain a liquid culture medium; inoculating the strain, fermenting for 18-24 hours, adding an accelerant in two times, shaking, and continuously culturing for 5-6 days. According to the phellinus igniarius polysaccharide synthesis system based on the carbon metabolic flux optimal distribution mechanism, components of the liquid culture medium are optimized, and the accelerant is added at a proper time, so that more carbon metabolism of the strain is used for mycelium growth in the early stage, and more carbon metabolism is used for phellinus igniarius polysaccharide synthesis through stimulation of the accelerant in the middle and later stages; therefore, the contents of the fermented mycelium and the phellinus igniarius polysaccharide reach a relatively high level, and the fermentation period is relatively short.

The invention relates to the technical field of resource utilization of agricultural wastes, and discloses a method for preparing an organic fertilizer by resource utilization of pickled vegetable residues, which comprises the following steps: step 1, pretreatment; 2, inoculating a composite strain accounting for 3% of the dry weight of the rotten vegetable leaves, wherein the total bacterial amount is greater than or equal to 1.5 * 10 < 9 > CFU / g; step 3, segmented fermentation: the first stage is an acid production-sodium discharge stage, and the second stage is a desalination-flocculation stage; step 4, carrying out solid-liquid separation; step five, performing secondary fermentation; and step 6, quality regulation and packaging. According to the method disclosed by the invention, efficient desalination and organic matter degradation in a high-salt environment are realized through division and cooperation of bacillus amyloliquefaciens dominated exopolysaccharide (EPS) synthesis, salt-tolerant single cell active sodium removal, salt-tolerant lactobacillus plantarum acid production and infectious microbe inhibition, and salt-tolerant saccharomyces cerevisiae osmotic pressure regulation; the first-stage acid sodium removal and the second-stage desalination flocculation control are matched with the microbial metabolism rule to improve the efficiency, high-salt inhibition is avoided, and efficient resource utilization of the pickled vegetable leftovers is achieved.

This invention discloses a gene of HmMYB73, a member of the MYB family of Arabidopsis thaliana, and its application in polysaccharide synthesis and salt stress tolerance in Arabidopsis thaliana. The nucleotide sequence of the HmMYB73 gene is shown in SEQ ID NO: 1. The recombinant vector pCAMBIA1303-HmMYB73 contains the nucleotide sequence shown in SEQ ID NO: 1. This gene participates in polysaccharide synthesis and salt stress tolerance in transgenic Arabidopsis thaliana, providing a foundation for the development and utilization of Arabidopsis thaliana through genetic engineering.

The present application relates to a kind of Eupenicillium fusion strain and its fermentation culture and application, belong to strain fermentation technical field.The content of active ingredients such as cordycepin, polysaccharide in the secondary metabolites of Eupenicillium F2652 of the present application is significantly improved, realizes the conversion and enrichment of polysaccharide of Eupenicillium strain while improving the content of cordycepin, the marker component of Cordyceps genus fungi.The fermentation culture obtained by liquid submerged fermentation of Eupenicillium F2652, the advantages of both parents are fused, both retain excellent composite polysaccharide synthesis ability, and also fuse good cordycepin accumulation potential, possess the development high cordycepin content Eupenicillium culture, it is conducive to enrich its as functional feed additive in different animals Practical application.