6 results about "Peptide Synthetases" patented technology

This invention discloses a Bacillus bellis strain overexpressing a lipopeptide synthase gene, its construction method, and its application in fruit preservation. It belongs to the fields of microbial genetic engineering and postharvest fruit preservation technology. Using Bacillus bellis QB250122 as the starting strain, two rounds of genome editing were performed using a dual-plasmid temperature-sensitive CRISPR-Cas9n system. In the first round, the srfA promoter was replaced with the PHpaII superpromoter. In the second round, a complete expression cassette was inserted at the bacA site. The engineered strain produced 900-1200 mg / L of surfactantin. Applying a bacterial suspension to the surface of fruits such as mangoes can extend shelf life by 10-15 days.

The invention belongs to the technical field of genetic engineering and synthetic biology, and particularly relates to a discontinuous paired homologous arm mediated Red / ET homologous recombination method and application thereof. According to the method, a discontinuous paired homologous arm mediated homologous recombination engineering technology is utilized, and the method is essentially different from traditional Red / ET type recombinase mediated continuous homologous arm homologous recombination. Experiments prove that the method can be applied to modular gene cluster transformation of non-ribosome polypeptide synthetase (NRPS), the transformation efficiency of the NRPS is remarkably improved, the transformation success rate of natural products synthesized by the NRPS is further greatly improved, and a key technical support is provided for fully releasing the application potential of the active natural products. Therefore, the method is not only an innovation and an effective supplement of the existing Red / ET class editing method, but also an ideal expansion of the current genetic engineering technology system, and has good practicability and wide application value.

The invention discloses an engineering strain and application of the engineering strain in preparation of pneumocandin. The engineering strain does not express a GloA-A2 gene, and expresses a non-ribosomal peptide synthetase gene CENRPS-A2 or CCNRPS-A2, so that the proportion of PB0-ser in a fermentation product can be adjusted, the generation of PB0-ser and PB0 is controlled from the source, and the cost for separating PB0-ser and PB0 is reduced.

The application discloses an amino acid sequence of tranexamic acid-carnosine ligase, and a preparation method of tranexamic acid-carnosine conjugate. The amino acid sequence of the tranexamic acid-carnosine ligase is shown as SEQ ID NO: 4. The tranexamic acid-carnosine ligase is fused by an adenylation (A) domain, a thioesterification (T) domain and a condensation (C) domain. The adenylation domain is obtained by mutation and modification of an adenylation domain in non-ribosomal peptide synthetase from Streptomyces coelicolor. After the mutation and modification, the adenylation domain has high specificity for a substrate tranexamic acid, can efficiently recognize and activate the tranexamic acid, so that the tranexamic acid-carnosine ligase can efficiently catalyze the reaction of the tranexamic acid and L-carnosine to generate the tranexamic acid-carnosine conjugate.

This invention discloses a bacterial strain and method for producing notoginseng extract, belonging to the field of bioengineering technology. This invention constructs recombinant cells or combinations of recombinant cells expressing alcohol dehydrogenase, amine dehydrogenase, ATP-dependent peptide synthase, polyphosphokinase 2-I, and polyphosphokinase 2-II, or replaces polyphosphokinase 2-I and polyphosphokinase 2-II with polyphosphokinase 2-III. The recombinant cells or combinations of recombinant cells are used to catalyze the synthesis of notoginseng extract from serine and oxalic acid. Using 100 g / L L-serine as a substrate, a maximum yield of 173 g / L L-notoginseng extract can be obtained. Therefore, this invention has good prospects for industrial application.

The present invention provides a genetically modified host cell capable of producing Porphyra-334 and / or Shinorine, which comprises (a) (i) a 2-demethyl-4-deoxycod's alcohol synthase (DDGS), (ii) an O-methyltransferase (O-MT or OMT), (iii) an ATP dependent carboxylic acid-amine ligase, and (iv) a non-ribosomal peptide synthetase (NRPS) or a D-ala-D-ala ligase, MysD or MysE; or (b) MysA, MysB, MysC or MysD, MysE or NRPS; wherein one or more of the foregoing enzymes are their homologous enzymes.