59 results about "Chitobiose" patented technology

The invention relates to a chitinase gene chiC and encoded protein and application thereof, and belongs to the technical field of genetic engineering. According to the chitinase gene chiC and the encoded protein and the application thereof, pseudoalteromonas sp. DL-6 serves as a research object, the chitinase gene chiC with a nucleotide sequence showed in SEQ ID No 1 is cloned for the first time, and a high-activity chitinase is obtained. The preparation method of the high-activity chitinase is simple, the production cost is low, a product is easy to conserve, the appropriate hydrolysis temperature is 30 DEG C, The enzyme-decomposed PH is 9.0, high degradation activity of a colloidal chitin can reach to 1.569 + / - 0.017 U / ml, the chitinase chiC degrades an aipha chitin and a beta chitin to generate a chitobiose, and industrial production prospect is possessed.

The invention relates to a preparation method and application of chitobiose. The preparation method comprises the following steps of dissolving chitobiose in glacial acetic acid solution; adding hydrogen peroxide; heating and stirring until the temperature is 40-90 DEG C and incubating; precipitating with ethanol after reaction is finished; filtering; and drying filter residues to obtain the chitobiose. The prepared chitobiose is used for preparing medicines for suppressing 10 strains of tumor cells of 5 kinds of humanized tumors. Biological compatibility and tumor atagonistics activity of the chitobiose are utilized effectively. By analyzing antitumor activity of the chitobiose, development of anti-tumor medicaments is promoted. The invention is used for the field of anti-tumor medicines.

The invention discloses a detection method for a total content of chitosan oligosaccharides with a polymerization degree of 2 to 6. The detection method comprises the steps that firstly chitosan oligosaccharides standard substances (chitobiose, chitotriose, chitotetraose, chitopentaose, chitohexaose) and a chitosan oligosaccharides sample are matched to have an appropriate concentration, and injected into a high performance liquid chromatograph so as to be analyzed by high performance liquid chromatography; subsequently, the peak retention time and the peak area of the chitosan oligosaccharides standard substances are recorded, and the peak retention time and the peak area of the chitosan oligosaccharides sample are also recorded, thereby the chitosan oligosaccharides with the polymerization degree of 2 to 6 corresponding to each peak in the sample are determined by comparison with the peak retention time of the standard substances; finally, the concentration of the chitosan oligosaccharides with the polymerization degree of 2 to 6 in the sample is calculated from the ratio of the concentration to the peak area of the standard substances and the peak area of chitosan oligosaccharides with the polymerization degree of 2 to 6 in the sample, so that the total content of the chitosan oligosaccharides with the polymerization degree of 2 to 6 is calculated by the ratio of the concentration of the chitosan oligosaccharides with the polymerization degree of 2 to 6 to the sample preparation concentration. The detection method for the total content of the chitosan oligosaccharides with the polymerization degree of 2 to 6 fills the blank of content detection of chitosan oligosaccharides in the industry.

The invention relates to chitinase CmChi6 gene and cloning expression and application thereof. In the invention, exochitinase CmChi6 gene with the nucleotide sequence shown in SEQ ID No.1 is firstly cloned, and exochitinase with high activity is obtained. The preparation method is simple, the production cost is low, the product is easy to preserve, the suitable enzymolysis temperature is 45 DEG C,the optimum pH for enzymolysis is 7.4, the thermal stability is good at 25-50 DEG C, and the enzyme activity is maintained at 60% or above for 33 h; the optimum pH is 7.4, and the enzyme activity ismaintained at 75% or above for 33 h at pH of 7.0-10.0; Ba<2+> has a slight activation effect on the activity of CmChi6; CmChi6 has high degradation activity on colloid chitin, and can be used to prepare chitobiose, with high conversion rate, low energy consumption, environmental friendliness, and important economic value in application of industrial degrading of chitin.

A chitin degradating bacterium is deformed by genetic engineering means to obtain the chitobiose deficient efficient genetically engineered chitin-degradating bacterium. It can effectively degradate the crystalline and colloidal chitin. After the chitin substrate is directly added to the fermented liquid containing them cultured in shake flask, the chitin oligose product without chitin monose can be directly obtained.

The invention provides a marine streptomyces niveus chitosanase gene and application thereof. According to the preference of escherichia coli codon, a chitosanase coded gene(GenBank accession number:AQU65829) of the marine streptomyces niveus is optimized, the homology of an optimized nucleic acid sequence with an original nucleic acid sequence is 73.39%, the chitosanase SnCSN is successfully expressed in escherichia coli BL21 (DE3), and the obtained chitosanase SnCSN can efficiently degrade chitosan to obtain chitosan oligosaccharide with chitobiose as a main product; and the chitosanase SnCSN has higher hydrolytic activity on chitosan substrates with different degrees of deacetylation, and complex chitosan oligosaccharide with different degrees of deacetylation is obtained. The chitosanase can be used for large-scale preparation of chitosan oligosaccharide and chitin oligosaccharide, and the industrial application prospects are good.

The invention relates to a chitosan deacetylase combined mutant with optimal pH reduction. The chitosan deacetylase combined mutant is prepared by the following steps: analyzing and predicting chitosan deacetylase surface charge and enzyme activity related sites through a molecular model and a computer, constructing mutants of the related sites through a site-directed mutagenesis technology, screening out single mutants with optimal pH, enzyme activity and product GlcN stability during mutation of different sites, and constructing a combined mutant, thereby obtaining the combined mutant with the optimal pH reduced to 6.0 and the obviously improved enzyme activity.

The invention belongs to the technical field of enzymes, and particularly relates to a chitosanase mutant and application thereof. The chitosanase mutant is characterized in that glycine at the 21 position of CsnMY002 wild type chitosanase is mutated into lysine. Compared with a wild strain, the chitosanase mutant has the advantages that chitosan oligosaccharide can be converted into chitobiose ina more targeted mode, separation is simpler, and the yield of a target product is higher.