9 results about "Chitobiose" patented technology

The present application relates to a kind of chitosanase mutant WP-E80A, plasmid, recombinant bacteria and its application, belong to enzyme engineering technical field, the amino acid sequence of the chitosanase mutant as shown in SEQ ID NO:1, the amino acid sequence of wild-type chitosanase CsnWP as shown in SEQ ID NO:2.Compared with wild-type chitosanase CsnWP, the 80th amino acid is subjected to site-directed mutagenesis.The present application also provides plasmid and recombinant engineering bacteria comprising the chitosanase mutant WP-E80A gene, and the chitosanase mutant WP-E80A can be prepared to generate chitotriose with chitobiose as substrate.

The invention relates to the technical field of gene engineering, and particularly discloses exo-chitinase Cq181 and application thereof in preparation of chitobiose. The amino acid sequence of the chitinase is as shown in SEQ ID NO: 1, and the nucleotide sequence of a Cq181 gene for coding the chitinase is as shown in SEQ ID NO: 2. According to determination, the molecular mass of the chitinase is 82.53 kDa, the chitinase shows high activity and specific production of chitobiose under the conditions that the temperature is 40 DEG C and the pH value is 7.0, and the chitinase is suitable for a mild and low-energy-consumption biological manufacturing process and particularly has good application potential in the aspect of preparing chitosan oligosaccharide with a specific polymerization degree (the polymerization degree is 2).

The invention discloses pichia pastoris engineering bacteria capable of efficiently expressing chitinase and application of the pichia pastoris engineering bacteria in shrimp shell high-value processing, and belongs to the field of biological engineering. The pichia pastoris engineering bacterium takes pichia pastoris GS115 as a host, the high-purity CtChi70 enzyme preparation can be prepared by signal peptide optimization, high-copy strain screening and cofactor overexpression in combination with high-density fermentation in a fermentation tank, ultrafiltration concentration in a hollow fiber column and freeze-drying flow, and CtChi70 accounts for more than or equal to 90% of total protein in fermentation liquor. The lyophilized enzyme preparation is used for a chitin substrate extracted from shrimp shells after mild treatment, and a product mainly comprising chitobiose can be efficiently generated. According to the invention, high yield of CtChi70 and simple preparation of the preparation are realized, and an economical, environment-friendly and high-yield feasible path is provided for high-value utilization of waste shrimp shell resources.

The invention discloses an anti-aging beautifying oral liquid containing low-polymerization-degree chitosan oligosaccharide and a preparation method thereof, and belongs to the technical field of marine organisms. Chitosan oligosaccharide mainly comprising chitobiose and chitotriose is prepared by utilizing the synergistic fermentation effect of microorganisms, and the chitosan oligosaccharide is compounded with collagen, sodium hyaluronate, vitamin C and the like to prepare the oral liquid. The low-polymerization-degree chitosan oligosaccharide is an excellent in-vivo antioxidant, can remove excessive free radicals, inhibit lipid peroxidation and slow down damage of metabolites such as peroxided lipid to the body, and then the anti-aging effect is achieved; the anti-aging and beautifying oral liquid prepared by matching natural moisturizing and beautifying components such as collagen and sodium hyaluronate is good in taste and easy to absorb, and animal experiment results show that the anti-aging and beautifying oral liquid can have beautifying and anti-aging effects after being frequently taken.

The application belongs to the technical field of enzyme engineering, and discloses a chitosanase mutant for producing chitobiose. A new 46 family glycoside hydrolase chitosanase (BsCsn46A) cloned from Bacillus subtilis is subjected to site-directed mutation, and the amino acid sequence is shown as SEQ ID NO:1. The chitosanase mutant is G21W, E235R and Y236K. Through hydrolysis reaction analysis, it is found that, different from the original enzyme hydrolysis chitosan product chitobiose (COS2) and chitotriose (COS3), the hydrolysis product of the mutant chitosanase is mainly COS2.

The application discloses a chitinase mutant D615S with high thermal stability and a construction method and application thereof. A wild-type chitinase Chil is subjected to thermal stability modification through a semi-rational design method, and a point mutation of aspartic acid at the 615th position is changed into serine, so that the half-life of the obtained mutant at 40 DEG C is increased by 3.6 times, and the half-life at 45 DEG C is increased by 24 times. When 100 g / L powder chitin is degraded at 45 DEG C for 60 h, 48 g / L reducing sugar is obtained, and the degradation rate is 48%; when 100 g / L lobster shells with 20% chitin content are degraded for 60 h, 9 g / L reducing sugar is obtained, and the degradation rate can reach 45%; through identification of the degradation products, it is found that the products are N acetylglucosamine and chitobiose with a mass ratio of 4:1, and have a good market prospect.

The invention relates to the technical field of gene engineering, and particularly discloses three-function chitinase CmChi18B as well as an expression method and application thereof. The amino acid sequence of the CmChi18B is shown as SEQ ID No.1, the CmChi18B has the activity of chitobiose excision enzyme, the activity of chitin incision enzyme and the activity of beta-N-acetylglucosaminidase at the same time, and the enzyme activity reaches 7.04 U / mg. The enzyme can independently and efficiently convert chitin into GlcNAc in a low-temperature environment, colloid chitin can be efficiently converted into GlcNAc after the enzyme acts for 24 hours under the conditions that the temperature is 30 DEG C and the pH value is 5.5, the conversion rate reaches 91.15%, and the product purity exceeds 98%. The CmChi18B has low-temperature adaptability and a wide pH tolerance range. The invention provides an efficient and environment-friendly enzymolysis technology for high-value utilization of marine biomass resources, and is suitable for the fields of foods, medicines, cosmetics and the like.

The present invention belongs to the field of enzyme engineering technology and specifically relates to a thermostable chitinase mutant and its application. The specific technical solution includes: a chitinase mutant, based on a wild-type chitinase, undergoing any one or more of the following mutations: mutation of serine at position 67 to glycine, lysine at position 177 to arginine, alanine at position 220 to valine, asparagine at position 257 to tyrosine, and asparagine at position 271 to glutamate; the amino acid sequence of the wild-type chitinase is shown in SEQ ID NO: 1. Compared with the wild-type chitinase, the mutant exhibits no significant change in its chitin degradation pattern, with chitobiose still being the primary hydrolysis product; however, the mutant exhibits significantly higher optimal reaction and melting temperatures, and a significantly prolonged half-life at 60°C, suggesting significant application potential.

The invention discloses a chitosanase mutant capable of producing chitobiose and application of the chitosanase mutant. The chitosanase mutant is derived from glucoside hydrolase chitosanase of a bacillus subtilis GH46 family, and compared with wild type chitosanase producing chitodisaccharide and chitotriose, the chitosanase mutant has the advantage that the hydrolysate is mainly chitodisaccharide. According to the invention, two chitosanase mutants are obtained, and the mutants are obtained by site-specific mutagenesis of tyrosine at the 236th site into arginine and glycine on the basis of wild chitosanase. The mutant can hydrolyze chitosan under mild conditions to produce chitosan oligosaccharide with single polymerization degree, and provides great help for separation and purification work in chitosan oligosaccharide production.