3 results about "Cyclodextrin glycosyltransferase" patented technology

The disclosure discloses a cyclodextrin glycosyltransferase with enhanced solvent tolerance and preparation thereof, belonging to the technical fields of enzyme engineering and genetic engineering. The disclosure constructs four cyclodextrin glycosyltransferase mutants with enhanced organic solvent tolerance. Among them, the mutant with the optimal tolerance to DMSO and methanol is G539I / R146F / D147N, which is 1.6 times and 1.7 times higher than that of WT, respectively; the mutant with the optimal tolerance to ethanol is R146F, which is 1.4 times higher than that of WT; the mutant with the optimal tolerance to acetone is G539I / R146F, which is 1.5 times higher than that of WT. The disclosure helps to expand the application of glycosyltransferases in organic reaction systems, improves the enzymatic efficiency of CGTase on natural hydrophobic substrates, and has great application prospects.

The invention is applicable to the technical field of functional tea drink processing, and provides a preparation method of monascus summer tea, which comprises the following steps: carrying out synergistic pretreatment of pulsed electric field and compound enzymolysis on summer tea; inoculating a compound microbial agent composed of monascus, aspergillus niger and lactobacillus plantarum for fermentation; the synthesis of different metabolites is accurately regulated and controlled by adopting a four-stage dynamic temperature change process; a targeted activator system composed of L-arabinose, vitamin C and betaine is added in a key metabolism window stage; an in-situ enzymatic glycosylation system composed of cyclodextrin glycosyl transferase and sucrose synthase is introduced, and monacolin K and tea polyphenol are modified. According to the invention, pH / temperature dual-response targeted activation, fructo-oligosaccharide synergistic in-situ glycosylation and stable network construction are fused with multi-strain synergistic fermentation and dynamic metabolism regulation for the first time, so that the yield, bioavailability, flavor quality and storage stability of monacolin K in a final product are remarkably improved.

The present invention belongs to the field of genetic engineering and enzyme engineering technology, and specifically relates to a cyclodextrin glycosyltransferase mutant and its application in the synthesis of rebaudioside RI. Specifically, the present invention uses the theory of directed evolution to transform the enzyme molecule, thereby successfully obtaining a cyclodextrin glycosyltransferase mutant. At the same time, the cyclodextrin glycosyltransferase mutant is used to replace the expensive UDP-glucose with cheap and easily available cyclodextrin as a glycosyl donor, and the catalytic efficiency is greatly improved, with a conversion rate of 98.8%. This reaction has opened up a new way to prepare rebaudioside RI, the product yield of the reaction is high, the preparation process is simple, it is suitable for industrial production, and has broad application prospects.