Abstract:Lipopolysaccharide (LPS), a major component in the outer membrane of Escherichia coli, possesses immunogenic properties and holds significant potential for medical applications. The LPS molecule typically consists of three parts: lipid A, a core oligosaccharide and O-antigen. Individual deletion of rapZ、fabF or ptsO gene in E. coli MG1655 increased LPS production by 25.0%, 27.6% or 14.6%, respectively. MWD001 was constructed by simultaneously deleting all the three genes in MG1655, and a 30.6% increase in LPS production was achieved, with LPS yield per gram of dry cell weight (DCW) rising from 7.73 mg in the parental strain MG1655 to 10.10 mg in MWD001. Finally, an arabinose-induced promoter PBAD was inserted upstream of the key gene cluster lpxD-fabZ-lpxA-lpxB in MWD001 genome, further increasing LPS production to 12.24 mg. These findings demonstrate that deletion of rapZ、fabF and ptsO genes, combined with overexpressing of the gene cluster lpxD-fabZ-lpxA-lpxB, significantly improves LPS production in E. coli.
