| 초록 |
Fumaric acid, a C4 dicarboxylic acid, is a precursor for diverse chemicals. To produce fumaric acid in E. coli, rational metabolic engineering strategies were employed. The local regulatory gene iclR was deleted to open the glyoxylate shunt and three fumarase genes were sequentially deleted. Next, plasmid-based overexpression of the native ppc gene, encoding phosphoenolpyruvate carboxylase, was performed. Then, the arcA and ptsG genes were sequentially deleted to increase the oxidative TCA cycle flux, and the aspA gene was deleted to block the conversion route. To avoid the use of inducer, the lacI gene was also deleted. The native promoter of the galP gene was replaced with strong trc promoter to increase glucose uptake rate. Fed-batch culture of the final strain produced 28.2 g/L fumaric acid in 63 h with overall yield and productivity of 0.389 g fumaric acid/g glucose and 0.448 g/L/h. In future works, systems metabolic engineering and process optimization could improve the production of fumaric acid. (Development of systems metabolic engineering platform technologies for biorefineries; NRF-2012-C1AAA001-2012M1A2A2026556) funded by the Ministry of Education, Science and Technology) |
