6 results about "Trehalose synthase" patented technology

This invention discloses a highly efficient method for preparing trehalose and its application, relating to the field of enzyme engineering. The invention obtains mutants with significantly increased enzyme activity by site-directed mutagenesis (D142T, F183A, R216Y) of trehalose synthase derived from *Streptomyces cerevisiae*. The triple mutant (D142T / F183A / R216Y) exhibits a specific enzyme activity of 72.1 U / mg, a 105% increase compared to the wild type; after incubation at 40℃ for 1 hour, the enzyme activity retention rate exceeds 90%. Using recombinant *E. coli* for shake-flask fermentation with 300 g / L maltose as a substrate, the trehalose yield reaches 269.8 g / L, with a conversion rate of 89.9%. The mutants and preparation method provided by this invention have advantages such as high enzyme activity, strong thermal stability, and high conversion rate, making them suitable for the industrial production of trehalose.

The invention discloses an efficient preparation method and application of trehalose, and relates to the field of enzyme engineering. According to the invention, trehalose synthase derived from streptomyces coelicolor is subjected to site-directed mutagenesis (D142T, F183A, R216Y), such that a mutant with substantially improved enzyme activity is obtained. The specific enzyme activity of the three mutants (D142T / F183A / R216Y) reaches 72.1 U / mg and is improved by 105% compared with that of a wild type; and the enzyme activity retention rate exceeds 90% after heat preservation at 40 DEG C for 1 h. The recombinant escherichia coli is used for shake flask fermentation, 300 g / L maltose is used as a substrate, the yield of the trehalose reaches 269.8 g / L, and the conversion rate is 89.9%. The mutant and the preparation method provided by the invention have the advantages of high enzyme activity, strong thermal stability, high conversion rate and the like, and are suitable for industrial production of trehalose.

The invention provides a glycosyl transferase mutant and application thereof in production of trehalose, and relates to the technical field of enzyme engineering. A semi-rational strategy is adopted, the trehalose conversion rate of the glycosyl transferase is improved through structure prediction, molecular docking and proline scanning mutation, the obtained glycosyl transferase mutant is obtained by mutating 54th serine of a starting sequence as shown in SEQ ID NO.1 into proline, and compared with a wild type, the catalytic activity is improved by 60.1%, and the thermal stability is improved by 4.7 times. The glycosyl transferase mutant is added into a double-enzyme trehalose synthesis system composed of maltooligosyl trehalose synthase and maltooligosyl trehalose hydrolase, the trehalose conversion rate reaches 84.71%, and the glycosyl transferase mutant is suitable for industrial production of trehalose and has wide application prospects in the fields of medicine, food, cosmetics, agricultural products and the like.

The invention discloses a group of nocardia seriolae trehalose synthase genes and a construction method of a deletion strain of the nocardia seriolae trehalose synthase genes, and belongs to the technical field of nocardia seriolae research. Comprising the following steps: nocardia seriolae culture and whole genome extraction, trehalose synthase gene cloning, deletion plasmid construction, competent cell preparation, electrotransformation and deletion strain screening, and deletion strain feature verification. Trehalose synthase genes of nocardia seriolae tpp, treS, treZ and the like are cloned, and the deletion strain is successfully constructed by using a homologous recombination technology, so that the key effect of the genes in the trehalose synthesis of the nocardia seriolae is defined, the close association of the trehalose content with the strain form, growth characteristics and toxicity is disclosed, and the application prospect is wide. The method provides important theoretical support for deep analysis of nocardia seriolae nocardia pathogenesis, and lays a solid foundation for novel prevention and control target screening and prevention and control strategy formulation of fish nocardia seriolae.

The invention discloses a papaya Pleurotus geesteranus trehalose synthase gene PmTPS as well as an encoding protein, dsRNA and application thereof, belongs to the technical field of molecular biology, and particularly relates to the papaya Pleurotus geesteranus trehalose synthase gene PmTPS which is PmTPS1 and PmTPS2, the nucleotide sequence of the PmTPS1 is as shown in SEQ ID NO.1, and the nucleotide sequence of the PmTPS2 is as shown in SEQ ID NO.2. The invention further discloses a preparation method of the papaya Pleurotus geesteranus trehalose synthase gene PmTPS. According to the dsRNA of the gene PmTPS, the dsRNA is PmTPS 1-dsRNA and PmTPS 2-dsRNA, the nucleotide sequence of the PmTPS 1-dsRNA is as shown in SEQ ID NO.3, and the nucleotide sequence of the PmTPS 2-dsRNA is as shown in SEQ ID NO.4. The dsRNA of the gene PmTPS comprises the dsRNA of the gene PmTPS, the dsRNA of the gene PmTPS and the dsRNA of the gene PmTPS. The dsRNA is used for inhibiting the expression of the papaya Pleurotus geesteranus trehalose synthase gene PmTPS, so that the papaya Pleurotus geesteranus is prevented and treated.

The invention belongs to the field of gene engineering and enzyme engineering, and particularly relates to an MTSase mutant with improved protein expression quantity and trehalose yield and application of the MTSase mutant in production of trehalose. The MTSase mutant contains 264th amino acid substitution and also contains a hydrotropy tag. The MTSase constructed by the invention is higher in expression quantity, better in solubility, stronger in stability and higher in enzyme activity, and has potential and wide application value in industrial production of trehalose.