Development of a Metabolically Engineered Strain for the Production of Beta Alanine, a Precursor for Nylon-3 Synthesis

Abstract

Metabolic engineering strategies were taken to produce 3-aminopropionicacid (3-AP), an important platform chemical for manufacturing acrylamideand acrylonitrile, in Escherichia coli. Using a fumaric-acid producing E.coli strain as a host, the C. glutamicumpanD gene (encoding L-aspartate-α-decarboxylase) was overexpressed and the native promoter of the aspAgene was replaced with the strong trc promoter. Additional overexpressionof the aspA and phosphoenolpyruvate carboxylase (ppc) genes, and thesupplementation of ammonium sulfate in the medium allowed productionof 3.49 g/L 3-AP. Fed-batch culture of the final strain yielded 17.9 g/L3-AP in 89 h, with an overall yield and productivity of 0.186 g 3-AP/gglucose and 0.200 g/L/h, respectively. (Technology Development Programto Solve Climate Changes on Systems Metabolic Engineering forBiorefineries from the Ministry of Science, ICT and Future Planning(MSIP) through the National Research Foundation (NRF) of Korea)