Gamma-Aminobutyric Acid Production Via GABA Shunt By the Introduction of Synthetic Scaffolds in Recombinant Escherichia coli

Nylon 4 is a biodegradable polymer which can be produced from the monomer of pyrrolidone. Gamma-aminobutyric acid (GABA) is a precursor of pyrrolidone used for the  production of bioplastics. In this study, Escherichia coli were engineered to produce gamma-aminobutyric acid from glucose via an alternative novel pathway by the introduction of synthetic scaffolds. The GABA pathway constructed contained succinate dehydrogenase, succinate-semialdehyde dehydrogenase and GABA aminotransferase to redirect the Krebs cycle flux to GABA production. By introduction of a synthetic scaffold, production of 0.64 g/L GABA was achieved at 30oC and pH 6.5. Final GABA concentration was increased by 11.3% via the inactivation of competing pathways, and higher initial glucose concentration led to the enhanced final GABA concentration of 1.01 g/L. This work was supported by a grant from the Next-Generation BioGreen 21 Program (SSAC, grant number: PJ01111601) by RDA, and Basic Science Research Program by the Ministry of Education (NRF-2014R1A1A2054726).