A low endotoxin prokaryotic expression in E. coli mutant strain engineering and construction method

The present invention discloses a low endotoxin prokaryotic expression in E. coli mutant strain engineering and construction methods, belongs to the technical field of biological engineering. It is through the regulation of the bacterial genome Lipid A synthetic fatty acid chain msbB gene and the suicide plasmid by methods pagP gene and homologous recombination knockout, thereby reducing the number of lipid A fatty acid chains, to reduce the toxicity of lipopolysaccharides purpose, and the low copy plasmid expression pagL expression and protein by exogenously lpxE while removing the fatty acid chains and a phosphate group of lipid a to achieve lower strain within toxin activity. Constructed using the techniques described above low endotoxin prokaryotic expression in E. coli mutant engineered bacteria Escherichia coli BL21 (DE3) S004, Accession No. CCTCC NO.M2014473, preservation time is October 14, 2014, which generates LPS stimulated cells showed endotoxin activity decreased significantly, it is possible to lay the foundation for subsequent expression of foreign proteins and for targeted drug therapy using the engineered bacteria. CCTCC NO.M2014473 20141014