A kind of operon bacabc copy number multiplication and bacillus licheniformis knockout reca gene and its construction method

Abstract

The invention provides bacillus licheniformis DW2delta recA bacABCs for multiplying the operon bacABC copy number and knocking off a recA gene. The strain is preserved in the China Center for Type Culture Collection in wuhan on June 12th, 2014, and the preservation number is CCTCC NO:M2014251. The genome of the strain also has double characteristics of multiplying the operon bacABC copy number and knocking off the recA gene, and moreover when the bacillus licheniformis DW2delta recA bacABCs for multiplying the operon bacABC copy number and knocking off the recA gene is used in bacitracin production, the yield of bacitracin can be increased by 11.5%.

Description

technical field [0001] The present invention relates to an operon bacABC Copy number doubling and knockout recA Genetically engineered strains of Bacillus licheniformis. 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, the main production strain of bacitracin is Bacillus licheniformis ( Bacillus licheniformis ) and Bacillus subtilis ( Bacillus subtilis ), which is produced by microbial fermentation. [0004] Bacitracin is formed by condensation of amino acids through a sulfur template mechanism, while the operon bacABC It is the gene encoding three key enzymes ...

AI Technical Summary

Problems solved by technology

However, due to the operon bacABC The gene sequence is too long, about 42kb, so it is impossible to construct a plasmid expression vector containing such a large gene fragment, and it is impossible to realize the operon by constructing an episomal or integrated plasmid expression vector bacABC Copy number doubling, therefore, the operon bacABC Copy number gain of the

in addition, recA The gene is the gene encoding the bacterial DNA recombination protein, and the homologous sequences existing on the chromosome will undergo exchange and recombination under the action of the bacterial DNA recombination protein, which is unfavorable for the stability of the strain to maintain the copy number

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