title: Increased production of succinic acid in Escherichia coli by overexpression of malate dehydrogenase.
abstract: Escherichia coli NZN111 is a double mutant with inactivated lactate dehydrogenase and pyruvate formate-lyase. It cannot utilize glucose anaerobically because of its unusually high intracellular NADH/NAD(+) ratio. We have now constructed a recombinant strain, E. coli NZN111/pTrc99a-mdh, which, during anaerobic fermentation, produced 4.3 g succinic acid l(-1) from 13.5 g glucose l(-1). The NADH/NAD(+) ratio decreased from 0.64 to 0.26. Furthermore, dual-phase fermentation (aerobic growth followed by anaerobic phase) resulted in enhanced succinic acid production and reduced byproduct formation. The yield of succinic acid from glucose during the anaerobic phase was 0.72 g g(-1), and the productivity was 1.01 g l(-1) h(-1).
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, People's Republic of China.
authors.forename: Li-Ya
authors.initials: LY
authors.lastname: Liang
authors.forename: Rong-ming
authors.initials: RM
authors.lastname: Liu
authors.forename: Jiang-feng
authors.initials: JF
authors.lastname: Ma
authors.forename: Ke-quan
authors.initials: KQ
authors.lastname: Chen
authors.forename: Min
authors.initials: M
authors.lastname: Jiang
authors.forename: Ping
authors.initials: P
authors.lastname: Wei
mesh_terms: D004926:Escherichia coli / Q000502:physiology*; D024861:Genetic Enhancement / Q000379:methods*; D005947:Glucose / Q000378:metabolism*; D008291:Malate Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D019802:Succinic Acid / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D019802:Succinic Acid; D008291:Malate Dehydrogenase; D005947:Glucose