7results about How to "Simplify separation and purification steps" patented technology

The invention discloses a self-assembly enzyme for directional synthesis of uniform low molecular weight dextran, the self-assembly enzyme is named as YG-SpyTag-SpyCatcher-padex, the YG is a dextran sucrase gene (Genbank No.DQ345760), the padex is a dextran enzyme gene (Genbank No.KF999646.1), the SpyTag and the SpyCatcher are two specific oligopeptides, and aspartic acid in the SpyTag and lysine in the SpyCatcher spontaneously form an isopeptide bond. The invention belongs to the technical field of biology, and relates to an enzyme engineering technology. According to the invention, dextran sucrase derived from an escherichia coli genetically engineered bacterium BL21 (DE3)-YG-SpyTag and dextran enzyme derived from a pichia pastoris genetically engineered bacterium X33-SpyCatcher-padex are combined through a SpyTag-SpyCatcher protein covalent coupling system, and the obtained self-assembled enzyme can be used for catalyzing the substrate sucrose to be directly converted into dextran with the molecular weight of 3000 to 4000 Da.

The present application relates to the technical field of synthetic biology, in particular to a novel taxane acetyl hydrolase, nucleic acid molecule, biological material and application thereof. The acetyl hydrolase comprises at least one of the following sequences: the amino acid sequence of the enzyme shown in SEQ ID NO. 1, SEQ ID NO. 9, SEQ ID NO. 16, SEQ ID NO. 19, SEQ ID NO. 21, SEQ ID NO. 24 or a protein with the same function obtained by substitution and / or deletion and / or addition. The above-mentioned biological enzyme has stronger site selectivity and more controllable product spectrum, has clear regional selectivity for taxane acetyl hydrolysis, can reduce excessive hydrolysis and by-products caused by chemical hydrolysis or non-specific esterase, and has important value for green manufacturing application of taxane.

The invention belongs to the technical field of betaine purification, and particularly relates to a method for separating and purifying betaine, which comprises the following steps: S1, chemically synthesizing a betaine mother solution; s2, primary vacuum concentration; s3, primary crystallization / filtration: adding a poor solvent into the concentrated solution in S2, stirring, filtering, and respectively collecting a filter cake and filtrate; s4, secondary vacuum concentration: performing vacuum concentration on the filtrate in S3; when the solid content of the solution is 30wt%, adding an inhibitor for continuous concentration, and when salt crystallization occurs, stopping heating; s5, secondary crystallization / hot filtration: stirring and crystallizing the concentrated solution obtained in S4 for 2-8 hours, then filtering while hot to remove sodium chloride, cooling and diluting the filtrate, centrifuging to remove the inhibitor, and collecting the centrifugate; and S6, finished product drying: evaporating the centrifugate solvent in the step S5 to dryness and collecting a betaine finished product. The method disclosed by the invention is simple to operate, sodium chloride in betaine is separated at low cost, and the purity and the yield of the purified betaine are high.

The invention belongs to the technical field of fluorine chemical industry, and particularly relates to borane participated 2, 2-difluoroethanol preparation reaction. Comprising the following steps: (1) taking 1, 1-difluoro-2-chloroethane as a raw material, carrying out catalytic cracking reaction under the action of a catalyst, and rectifying to obtain 1, 1-difluoroethylene; (2) carrying out hydroboration reaction on 1, 1-difluoroethylene and a borane complex to prepare an alkyl boron solution; and (3) adding an oxidizing agent into the alkyl boron solution for continuous reaction, and distilling to obtain the 2, 2-difluoroethanol. According to the method, the byproduct R142 in R142b production is used as a raw material, so that the problem of subsequent treatment of the byproduct is solved; in the reaction process, a high-boiling-point aprotic solvent is abandoned, the separation and purification steps are simplified, the highly selective synthesis of the target product 2, 2-difluoroethanol is realized, the generation of an isomeride byproduct is effectively avoided, and the higher product yield is ensured.

The invention discloses a method for removing selenate and recovering elemental selenium, and belongs to the technical field of wastewater treatment and resource recovery. According to the method, an anaerobic dynamic biofilm reactor (AnDMBR) is used for treating the selenium-containing wastewater, selenate is reduced into elemental selenium through anaerobic microorganisms, and the elemental selenium is intercepted on a dynamic biofilm. After the operation of the reactor is finished, carrying out ultrasonic cell disruption treatment on the dynamic biological membrane, removing residual biomass on the surface of the selenium elementary substance by using alkali liquor, and then washing by using ultrapure water until the pH is neutral, thereby purifying and recovering the selenium elementary substance. The AnDMBR used in the invention can effectively remove selenate in wastewater, does not accumulate selenite with higher toxicity, and does not cause secondary pollution; the selenium elementary substance separation method is simple, and the separation and purification efficiency is high.

The invention belongs to the technical field of bioengineering, and particularly relates to a recombinant engineering bacterium, an immobilized cell, a preparation method and application, the recombinant engineering bacterium takes Escherichia coli as a chassis strain, the chassis strain contains an expression vector for expressing a target gene of sucrose invertase, and the immobilized cell is a recombinant cell. Or a target gene for expressing sucrose invertase is inserted into the chassis strain, the target gene is connected with a solubilizing protein SUMO tag or SSO tag, the SUMO tag is located at the N end of the target gene, and the SSO tag is located at the N end or C end of the target gene; the enzyme activity can be improved, the quality of the sucrose hydrolyzed syrup is improved, and the production cost is reduced.

The application provides a method for preparing fish skin collagen peptides with high antioxidant activity by DHPM and UIO-66 molecular imprinting, and relates to the technical fields of aquatic product deep processing and bioactive peptides. The method comprises the following steps: fish skin pretreatment, DHPM-induced collagen protein unfolding, endogenous enzyme autolysis, crude separation, selective target enrichment by using UIO-66 material with histidine as a molecular imprinting template, and drying collection. The application destroys the dense triple helix structure of collagen protein by using the physical field effect of dynamic high pressure microfluidization, exposes the enzyme cutting site, uses the endogenous enzyme of fish skin for autolysis, and then uses the histidine molecular imprinting UIO-66 material to accurately capture the high antioxidant activity peptide segment, so that the enzymolysis efficiency and the antioxidant activity of the product are significantly improved. The application does not need to add exogenous enzymes, and has the advantages of green process, low cost and high product purity. The obtained fish skin collagen peptides can be widely applied to the fields of functional food, cosmetics and medicine.