Bacillus licheniformis strain loaded with serine acetyl transferase gene as well as building method and application thereof

Abstract

The invention provides a bacillus licheniformis strain DW2 (pHY300-cysE) loaded with a serine acetyl transferase gene capable of producing at high yield, wherein the strain is preserved at the Typical Culture Preservation Centre in China in Wuhan, the preservation number is CCTCCNO:M2013402, and the preservation date is September 10, 2013. Application of the bacillus licheniformis loaded with the serine acetyl transferase gene cysE in bacitracin comprises the following steps: A, activating the strain; B, fermenting seeds; and C producing and fermenting. By adopting the bacillus licheniformis strain, the yield of the bacillus licheniformis is improved by 7%.

Description

technical field [0001] The invention relates to a bacillus licheniformis engineering strain carrying a serine acetyltransferase gene. Background technique [0002] Bacitracin is a light yellow or off-white powder, odorless and bitter in taste. It is a polypeptide antibiotic composed of 10 amino acids and 12 amino acid residues, which can effectively inhibit Gram-positive pathogenic bacteria and some Gram-negative bacteria. Bacitracin has the advantages of almost no absorption in the intestine, rapid excretion, and no residue in the body, so it is widely added to feed. [0003] At present, bacitracin is mostly produced by microbial fermentation, and its main production strain is Bacillus licheniformis ( Bacillus licheniformis ) and Bacillus subtilis ( Bacillus subtilis ). During the fermentation process of bacitracin, the supply of amino acid substrates has an important impact on its yield, and a reasonable and sufficient supply of amino acids can increase the yield of ba...

AI Technical Summary

Problems solved by technology

However, there are many disadvantages in this way of increasing the yield of bacitracin by adding cysteine ​​as feed: (1) the yield of bacitracin is still low; (2) when the amount of cysteine ​​added is large, the It takes a certain amount of time to dissolve, and the incompletely dissolved cysteine ​​is easy to deposit and block the pipe opening of the fermenter; (3) Artificially adding cysteine ​​to the medium will disrupt the normal metabolism of the production strain and affect the growth of the strain (4) The amount of cysteine ​​added is determined by the number of bacteria in the fermenter, and the amount of bacteria in the fermenter increases rapidly, so it is difficult to determine the amount of cysteine ​​added

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