Metabolic engineering of Escherichia coli for the production of L-aspartic acid

Abstract

Increasing demands for sustainable production of valuable chemicals, biorefinery process using microbial fermentation combined with metabolic engineering has been actively investigated for the past two decades. One of the important amino acids, L-aspartic acid, is a four carbon amino acid and mainly used as a raw material in the synthetic sweetener, aspartame. It can be a versatile platform chemical to produce other valuable derivative chemicals and biodegradable polymers. In this study, Escherichia coli was metabolically engineered to produce L-aspartic acid in glucose mineral salts medium. For the efficient production of L-aspartic acid, E. coli was engineered by overexpression of the native E. coli genes as well as regulating metabolic fluxes by knocking-out several genes. A 24-hour flask culture results showed the 245.1 mg/L of product accumulation. Further, increasing productivity of E. coli strain would have a great potential to make the production process more economically viable and competitive to current chemical production methods.