48 results about "Polysaccharide synthesis" patented technology

The invention discloses an Escherichia coli membrane wall-reduced chassis strain and the application of the high-yielding PHB strain, belonging to the fields of genetic engineering and fermentation engineering. The present invention knocks out the core sugar gene cluster gmhD-waaQ and the O-antigen gene cluster wbbL-rmlB of the lipopolysaccharide on the wild-type Escherichia coli W3110 genome, the extracellular polysaccharide gene cluster galF-wza, and the type 4 capsular polysaccharide synthesis gene cluster yccC- ymcD, three flagellar gene clusters flhE-motA, fliY-fliR, flgN-flgL, and a pilus gene cluster fimB-fimH to obtain strain WJW08, and then transform the genes related to PHB synthesis into the strain to obtain recombinant strain WJW08 / pBHR68, Under normal fermentation conditions, the recombinant bacterium can synthesize 81.9% PHB of dry cell weight, which is 54.6 times that of the wild control bacterium W3110 / pBHR68 (1.5%).

The preparation method of injectable self-adaptive natural hydrogel adhesive, first synthesizes gelatin-phenylboronic acid with carboxyphenylboronic acid and gelatin through amidation reaction, or synthesizes polysaccharide-phenylboronic acid with aminophenylboronic acid and natural polysaccharide; And through amidation React dopamine and gelatin or natural polysaccharides to synthesize gelatin-dopamine or polysaccharide-dopamine; then dissolve gelatin-phenylboronic acid / polysaccharide-phenylboronic acid in phosphate buffer solution, gelatin-dopamine / polysaccharide-dopamine in polyphenol-containing substances In the phosphate buffer solution, the two are mixed well, and the spontaneous esterification reaction between phenylboronic acid and polyphenols can occur, forming a reversible borate bond, and finally an injectable self-adaptive natural hydrogel adhesive is prepared. ; The hydrogel adhesive of the present invention has good bioadhesion and antibacterial and anti-inflammatory effects, and can be attached to the tissue surface and play a repairing role; it has good mechanical self-adaptive properties and can match different dynamic tissues deformation and frequency.

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.