3results about How to "High substrate concentration" patented technology

The application belongs to the field of biopharmacy and bioconversion, and particularly relates to a lipase mutant and application thereof. The lipase CALB mutant of the application is obtained by adopting single-point mutation or combined mutation on positions 40, 134, 154, 189, 278 and 281 of the amino acid sequence shown in SEQ ID NO. 1. The mutant greatly improves the stereoselectivity in catalyzing the production of (S)-3-cyclohexene-1-methyl formate from racemic 3-cyclohexene-1-methyl formate. Compared with the traditional chemical method for preparing (S)-3-cyclohexene-1-methyl formate, the lipase CALB mutant provided by the application has high stereoselectivity, mild reaction conditions, is friendly to the environment, has reduced requirements on equipment, greatly reduces the production cost, and shows a wide application prospect in industrial application.

The application provides a method for synthesizing dextroketoprofen. The method comprises the following steps: S1: taking ketoprofen amide as a raw material, performing a hydrolysis reaction in a reaction medium, a cosolvent, a phase transfer catalyst and an amidase system, and performing separation and purification to obtain dextroketoprofen and levo-ketoprofen amide; S2: performing a chemical racemization reaction on the levo-ketoprofen amide in the presence of a solvent and a base to obtain ketoprofen amide; and repeating step S1 by taking the ketoprofen amide as a raw material. The method has high substrate concentration, low enzyme substrate ratio, high selectivity, high conversion rate and high product purity, higher efficiency, low solvent consumption, lower cost, fully utilized raw materials, less solid waste discharge, can meet the requirements of industrialized production of enzyme catalysis, and has good industrial application potential.

The application provides an aspartase mutant and a method for producing R-3-aminobutyric acid by using the aspartase mutant, and belongs to the field of enzyme engineering. The amino acid sequence of the mutant is obtained by one or more times of mutation of the sequence shown in SEQ ID NO. 3. The mutant contains one or more of the four mutant sites at positions 237 (T237C), 31 (I31V), 88 (K88N) and 123 (G123S). The aspartase mutant of the application has the advantages of high catalytic activity and high selectivity. The cell obtained by fermentation can catalyze 300 g / L of substrate, which is the highest substrate concentration reported at present. When the aspartase mutant is used for synthesizing R-3-aminobutyric acid, the R-3-aminobutyric acid production rate and the chiral purity can reach more than 99% in 7 hours. Compared with the previous chemical synthesis method and biological enzyme method, the process is simple, the conversion rate is high, the production cost is relatively low, and the aspartase mutant has a good industrial application prospect.