46 results about "Polysaccharide synthesis" patented technology

The present invention relates to methodology for polymer grafting by a polysaccharide synthase and, more particularly, polymer grafting using the hyaluronate or chondroitin or heparin/heparosan synthases from Pasteurella, in order to create a variety of glycosaminoglycan oligosaccharides having a natural or chimeric or hybrid sugar structure with a targeted size that are substantially monodisperse in size. The present invention also relates to methodology for polymer grafting by a polysaccharide synthase to form glycosaminoglycan polymers having an unnatural structure.

This invention discloses compositions and methods for preparing chloroquine-coupled nucleic acid compositions. The prior art has shown that chloroquines given as free drug in high enough concentration, enhances the release of various agents from cellular endosomes into the cytoplasm. The purpose of these compositions is to provide a controlled amount of chloroquine at the same site where the nucleic acid needs to be released, thereby reducing the overall dosage needed. The compositions comprise a chloroquine substance coupled to a nucleic acid directly or through a variety of pharmaceutical carrier substances. The carrier substances include polysaccharides, synthetic polymers, proteins, micelles and other substances for carrying and releasing the chloroquine compositions in the body for therapeutic effect. The compositions can also include a biocleavable linkage for carrying and releasing nucleic acids for therapeutic or other medical uses. The invention also discloses nucleic acid carrier compositions that are coupled to targeting molecules for targeting the delivery of nucleic acids to their site of action.

Heparin is synthesized from a polysaccharide comprised of a 1-4 glycosidically linked alternating polymer of uronic acid and glucosamine residues, wherein the uronic acid is selected from iduronic and glucuronic acid, wherein the glucosamine is partially N-sulfated; by a series of selective reactions catalyzed by recombinant enzymes.

The production of a diutan polysaccharide exhibiting increased viscosity properties as compared with previously produced polysaccharide of the same type of repeating units. Such an improved diutan polysaccharide is produced through the generation of a derivative of Sphingomonas sp. ATCC 53159 that harbors a multicopy broad-host-range plasmid into which genes for biosynthesis of diutan polysaccharide have been cloned. The plasmid provides the capability within the host Sphingomonas strain to produce multiple copies of genes for such polysaccharide synthesis. In such a manner, a method of not just increased production of the target diutan polysaccharide, but also production of a diutan polysaccharide of improved physical properties (of the aforementioned higher viscosity) thereof is provided. Such a diutan polysaccharide has proven particularly useful as a possible viscosifier in oilfield applications and within cement materials. The inventive methods of production of such an improved diutan polysaccharide, as well as the novel cloned genes required to produce the improved diutan within such a method, are also encompassed within this invention. Additionally, the novel engineered Sphingomonas strain including the needed DNA sequence is encompassed within this invention.

The invention provides a synthetic medium for culturing a phellinus igniarius liquid. The synthetic medium takes glucose as a carbon source and 20 kinds of amino acid as a nitrogen source, and consists of inorganic salt and vitamin. The ratio of carbon to nitrogen is designed as 50 to 1; and the specific concentration g/l is as follows: the glucose: 30 to 80 grams; glutamic acid: 0.1 to 1.5 grams; glutamine: 0.1 to 1.5 grams; aspartic acid: 0.1 to 1.5 grams; asparagines: 0.1 to 1.5 grams; glutamic acid: 0.01 to 0.1 gram; tryptophan: 0.01 to 0.1 gram; valine: 0.01 to 0.1 gram; alanine: 0.01 to 0.1 gram; etc. During the whole culture process of the synthetic medium, phellinus igniarius mycelium is quick in growth; the yield of the phellinus igniarius mycelium can reach 20 grams per liter to the highest degree; simultaneously no agricultural and sideline product is introduced as the carbon source and the nitrogen source; substances such as proteins in the medium, medium compositions and so on are not carried; phellinus igniarius exopolysaccharide produced through fermentation has high purity and stable quality; and the yield of phellinus igniarius polysaccharide can reach 0.198 gram per liter to the highest degree. The synthetic medium has the advantages of clear compositions, stable quality and so on, and can be used for mass culture of the phellinus igniarius liquid and research of the regulation and control rule of polysaccharide anabolism.

The invention discloses extreme halophilic archaea engineering bacteria for producing bioplastics PHBV (Poly-(HydroxyButyrate-co-Hydroxy Valerate)) by effectively utilizing a carbon source. The recombined extreme halophilic archaea is extracellular polysaccharide synthesis function-deficient engineering bacteria obtained by deleting at least one protein function expressed by an extracellular polysaccharide synthesis cluster in the genome of the extreme halophilic archaea Haloferax mediterranei. The extreme halophilic archaea has the advantages that infectious microbe is not easy to pollute, PHA (Poly Hydroxy Alkanoate) is convenient to extract, the PHBV from a non-correlated carbon source can be synthesized, and the like, and is considered as a highly preponderant PHBV producing strain. The extracellular polysaccharide synthesis function-deficient strain engineering bacteria are characterized in that the polyhydroxyalkanoate can be produced from various carbon sources such as glucose, starch and whey more efficiently in contrast with a wild type strain, the concentration of the PHBV is 20% higher than that of the wild type strain under the same fermentation conditions, and the problems such as sticking, lots of bubbles and dissolved oxygen reduction of a culture solution caused by extracellular polysaccharide accumulation are also solved.

The invention discloses an application of a glycosyltransferase gene, namely an application of the glycosyltransferase gene in improving the synthesis of lactobacillus plantarum exopolysaccharides; wherein the glycosyltransferase gene is a gene orf1595 or a gene cps4I, the nucleotide sequence of the gene orf1595 is as shown in SEQ ID NO: 1, and the nucleotide sequence of the gene cps4I is as shownin SEQ ID NO: 2; an orf1595 or cps4I gene and a temperature-sensitive plasmid are recombined to construct a knockout vector, the knockout vector is introduced into a food-borne lactobacillus plantarum competent cell, and then a gene knockout strain is constructed through homologous recombination; a phenol sulfuric acid method is adopted to determine the exopolysaccharide production capacity of the strain, it is found that the exopolysaccharide production capacity of the knocked-out strain is lower than that of a wild strain, orf1595 or cps4I genes play a key role in exopolysaccharide synthesis, and the method has huge potential in the fields of exopolysaccharide biosynthesis research and application.

The invention discloses a method for increasing the yield of pullulan. The method comprises the following steps: after activating aureobasidium pullulans, inoculating a seed medium; after OD600 is greater than 0.3, inoculating seeds into a fermentation medium; monitoring OD600 of a fermentation liquid in real time; when OD600 is greater than 0.2 and less than 0.3, adding a compounding agent I which accounts for 0.02-0.03% of the volume of the fermentation liquid, so as to greatly increase the bacterium growth velocity and remarkably shorten the logarithmic growth phase; when OD600 is greater than or equal to 0.6, adding a compounding agent II which accounts for 0.03-0.05% of the volume of the fermentation liquid. The substrate conversion speed can be accelerated, the polysaccharide synthesis performance can be improved, and the yield can be greatly increased.

The invention discloses an abortus Brucella vaccine recombinant strain and an application thereof in preparing vaccine. The recombinant strain is a strain obtained by deactivating capsular polysaccharide synthesis protein gene and carboxyl uridine phosphate decarboxylase gene in the abortus Brucella strain S19. The obtained recombinant strain has small virulence and can be used as vaccines to immunize animals without needs of deactivation. The inoculated animal generates no lipopolysaccharide antibody and the virulent virus strain-infected animal can be distinguished from novel vaccine strain immunized animal by serological reaction. The recombinant strain is beneficial to improving the Brucella vaccine, researching diagnosis and identification reagents and developing the Brucella vaccine and matched diagnosis and identification reagents, and has extremely important significance in deracinating and purifying the global animal Brucella.

The invention relates to a synthesis and purification method of carboxymethylated ganoderma lucidum polysaccharide. The method includes the steps of: adding ganoderma lucidum polysaccharide and sodium hydroxide into a solvent to conduct stirring dissolving, then adding chloroacetic acid, carrying out stirring reaction at 65-85DEG C for 2-4h, performing cooling, adjusting the pH value to neutral, conducting alcohol precipitation and filtering, collecting the precipitate, then dissolving the precipitate in water, and carrying out alcohol precipitation, dialysis, and freeze drying to obtain light brown cotton-like carboxymethylated ganoderma lucidum crude polysaccharide. Test proves that: the carboxymethylated ganoderma lucidum polysaccharide provided by the invention has very good physical and sensory moisturizing effects, also can reduce cigarette stimulation and miscellaneous gas, improves the mellow and full sense and comfort of cigarette smoke, and can applied as an excellent performance tobacco humectants in cigarettes.

The invention discloses a use of sodium nitroprusside in ganoderma lucidum submerged fermentation for producing ganoderma lucidum polysaccharide. After ganoderma lucidum submerged fermentation solution culture lasting for 3-5 days, sodium nitroprusside as an inducer is added into a ganoderma lucidum submerged fermentation solution to induce ganoderma lucidum polysaccharide production in ganoderma lucidum submerged fermentation. Sodium nitroprusside crystals as nitric oxide donors are dissolved in water so that a sodium nitroprusside aqueous solution is formed and is used as an inducer for ganoderma lucidum submerged fermentation used for producing ganoderma lucidum polysaccharide. Through slowly releasing nitric oxide in cells, sodium nitroprusside can promote secondary metabolite ganoderma lucidum polysaccharide synthesis. A result of an experimental research shows that through utilization of an appropriate amount of sodium nitroprusside in a ganoderma lucidum fermentation solution, a ganoderma lucidum polysaccharide yield can be effectively increased by 25 to 160%.

The invention provides a method for eliminating a side product polysaccharide in fermentation production of pyrroloquinoline quinone. According to the method, in microorganism fermentation production of pyrroloquinoline quinone, a gene knockout method is used for knockout of an important gene in a polysaccharide synthetic gene cluster of a pyrroloquinoline quinone production strain so that the production strain loses the capability of exopolysaccharide synthesis without reducing the capability of producing pyrroloquinoline quinone. According to the method disclosed by the invention, the important gene mpq_1844 in the polysaccharide synthetic gene cluster of the PQQ (pyrroloquinoline quinone) production strain Methylovorussp.MP688 is successfully knocked out by a double-exchange homologous recombination method, the gene knockout strain of the original production strain no longer synthesizes exopolysaccharide, thus the metabolism side product polysaccharide generated in microorganism fermentation production of the pyrroloquinoline quinone is eliminated, the aim of simplifying the purification technique is achieved and the foundation is laid for industrial and efficient preparation of pyrroloquinoline quinone.

The invention discloses engineered Escherichia coli for high yielding capsular polysaccharide and a method for producing chondroitin by the aid of the capsular polysaccharide. Synthetic gene cluster transcriptional regulation factor slyA protein of the capsular polysaccharide is over expressed in the Escherichia coli, and expression of a synthetic gene cluster of the capsular polysaccharide in the Escherichia coli is promoted, so that the capsular polysaccharide produced by the Escherichia coli K4 is increased. The yield of the capsular polysaccharide after fermenting and culturing the engineered Escherichia coli is 112% higher than that of capsular polysaccharide produced by original bacteria, and the chondroitin with purity higher than 93% is obtained by means of collection and preparation. The engineered Escherichia coli and the method lay a certain foundation for developing fermentation production of chondroitin sulfate.

The invention discloses a method for preparing rhamnolipid and its special Pseudomonas aeruginosa. The method for preparing rhamnolipids includes 1) and 2): 1) constructing a recombinant Pseudomonas aeruginosa with reduced Psl polysaccharide synthesis ability and/or reduced Pel polysaccharide synthesis ability compared with Pseudomonas aeruginosa as the starting bacterium 2) fermenting the recombinant Pseudomonas aeruginosa to obtain rhamnolipids. The experiment of the present application proves that compared with Pseudomonas aeruginosa as the starting bacterium, the rhamnolipid synthesis ability of recombinant Pseudomonas aeruginosa with reduced Psl polysaccharide synthesis ability and/or reduced Pel polysaccharide synthesis ability is improved.

The invention discloses UDPG pyrophosphatase produced from aureobasidium pullulans, a coding gene, a carrier and application to improvement of the yield of exopolysaccharides of the aureobasidium pullulans. An amino acid sequence of the UDPG pyrophosphatase is as shown in SEQ ID NO.1. The gene engineering technology is utilized for over-expression of the UDPG pyrophosphatase in an original fungus of the aureobasidium pullulans, the yield of pulullan in recombined aureobasidium pullulans can be improved by 32%, the yield of beta-1,3 glucan in the recombined aureobasidium pullulans can be improved by 55%. The UDPG pyrophosphatase is proofed to participate in the synthesis of two exopolysaccharides from the molecular aspect, so as to provide a technological base and methodological guidance to modify a synthetic pathway of the exopolysaccharides of the aureobasidium pullulans according to the metabolic engineering technology.

The invention discloses S. pneumonia in the technical field of bio-pharmacy. The S. pneumonia comprises an S. pneumonia serum type strain, wherein the S. pneumonia serum type strain includes one or a plurality of kinds of capsular polysaccharide generating inhabiting genes with integral lack, partial lack, sequence point mutation or sequence point lack. When the capsular polysaccharide generating inhabiting genes have one or a plurality of kinds of changes of partial lack, sequence point mutation or lack, the function and the activity of the SPD-0064 genes or coded products of the SPD-0064 genes can be influenced; the goal of interfering or inhibiting the combination of SPD-0064 gene coding products and capsular polysaccharide gene clusters is achieved, so that the transcription function of the capsular polysaccharide gene clusters is interfered or damaged; the capsular polysaccharide yield is finally increased.

The invention belongs to the technical field of microbe polysaccharide and relates to high-specific heat capacity microbe biological polysaccharide and its preparation method and use. The preparation method comprises that a bacillus subtilis strain capable of effectively accumulating extracellular capsular polysaccharide is selected from nature and then is subjected to 16rs DNA identification, a polysaccharide synthesis approach-related gene is adjusted and modified so that a yield is improved, and through microbial fermentation, alcohol precipitation, and drying and refining, the high-specific heat capacity microbe biological polysaccharide is prepared. The high-specific heat capacity microbe biological polysaccharide has a structure skeleton mainly comprising glucose, galactose, mannose and glucuronic acid, has a side chain tail end obtained by connection polymerization of pyruvic acid and acetyl groups, is a polymer, has molecular weight of 5000-30000Da, is named as SM-1, has a good water retention capacity and a high-specific heat capacity, has moisture retention and infrared radiation resistance, and has a good application value in the cosmetic industry.

The present invention relates to a method of identifying a serotype of Klebsiella pneumoniae, in particular to a method using specific polymerase chain reaction (PCR) primer sets designed according to a fragment of a capsular polysaccharide synthesis (cps) region to identify a K57 or a NTUH-N1 serotype and its application. NTUH-N1 is a novel serotype which differs from the previously reported 77 serotypes. This PCR-based cps genotyping method not only solves the problems of insufficient specificity and sensitivity caused by conventional immune method, but can be applied in clinical diagnosis with the advantages of rapidity and low cost. In addition, the rate of unidentifiable strains can also be reduced by this method.

The invention relates to a synthesis and purification method for a carboxymethylation astragalus polysaccharide. The synthesis and purification method includes steps of stirring and dissolving an astragalus polysaccharide and sodium hydroxide in solvents; adding chloroacetate into the solvents; stirring the chloroacetate and the solvents to allow the chloroacetate and the solvents to react with one another for 3-4h at the temperatures of 50-70 DEG C to obtain products; cooling the products; regulating a pH (potential of hydrogen) value of the products until the products are neutralized; carrying out ethanol precipitation on the products; filtering the products; collecting precipitates; dissolving the precipitates in water; carrying out ethanol precipitation on the precipitates; dialyzing the precipitates; freezing and drying the precipitates to obtain a white flocculent carboxymethylation astragalus crude polysaccharide. The synthesis and purification method has the advantages that as proved by tests, excellent physical and sensual moisture retention effects can be realized for cigarettes by the carboxymethylation astragalus polysaccharide, irritation and offensive odor of the cigarettes can be reduced, the mellow and full sensation and the comfort of smoke of the cigarettes can be improved, and the carboxymethylation astragalus polysaccharide can be applied to the cigarettes as a tobacco humectant with excellent performance.