Deletion of arcA increased the production of acetyl-CoA-derived chemicals in recombinant Escherichia coli.

OBJECTIVE: Acetyl-CoA is used to produce many valuable metabolites in Escherichia coli. However, acetate overflow is a major shortcoming. Knockout of the global regulator gene, arcA, may solve this problem. RESULTS: The arcA gene of E. coli BL21(DE3) was knocked out, and the production of phloroglucinol (PG) and 3-hydroxypropionate (3HP), both derived from acetyl-CoA, were used to evaluate its effect. The arcA mutants had higher cell yields and higher glucose utilization efficiencies than the corresponding control strains, and the productions of PG and 3HP were 0.92 g/l and 0.27 g/l, respectively; more than twice that of the control strains. Furthermore, arcA knockout also showed significant repression on formation of acetate, the major byproduct in fermentation. Acetate concentrations were decreased 69.4 % and 87 % by arcA knockout during the production of PG and 3HP, respectively. CONCLUSIONS: The arcA gene knockout is a solution to acetate overflow and may improve production of a wide range of acetyl-CoA-derived metabolites.