Metabolic engineering for acetate control in large scale fermentation.

Escherichia coli is the most commonly used microorganism for production of recombinant proteins for different applications. Acetate accumulation during aerobic growth on glucose has significant negative impact on recombinant protein production in Escherichia coli. Various strategies, such as process and genetic approaches have been developed to limit acetate formation to increase the productivity of recombinant proteins. We developed a strategy to combine inactivation of pyruvate oxidase (poxB) and over-expression of acety-CoA synthetase (acs) in E. coli K strain for controlling acetate accumulation. A recombinant peptide was expressed and produced in the engineered strains with a very low acetate -formation in a 10-L fermentation process.