Construction of a High FFA-producing Strain by Integrating Previous Results

Abstract

Microbial production of free fatty acids (FFAs) and their derivatives is considered a promising approach for replacement of petroleum-based production of fuels and chemicals. In aspect of microbial production advantages, many studies have attempted to redesign microbes through metabolic engineering and synthetic biology for increased production of FFA. Since several studies have reported to improved fatty acid production using metabolic engineering and synthetic biology tools. The aim of this study is to construct a high FFA-producing E. coli strain by integrating previous results: 1) overexpression of transcriptional activator (FadR) of fatty acid synthesis, 2) heterologous expression of MMC converting OAA and acetyl-CoA to malonyl-CoA and pyruvate, 3) expressing a mutant TesA with high specific enzyme activity, and 4) deletion of FFA transport-related genes. The resulting strain improved FFA production up to 9.5-fold compared with the control strain expressing only the wild-type thioesterase. The combination showed synergistic effect on FFA production but did not increase as much as the arithmetic sum. These findings suggest that fine-tuning of multiple pathways is necessary for highly enhanced FFA production.