High-level succinic acid production and yield by lactose-induced expression of phosphoenolpyruvate carboxylase in ptsG mutant Escherichia coli.
Escherichia coli strains with foreign genes under the isopropyl-beta-D: -thiogalactopyranoside-inducible promoters such as lac, tac, and trc were engineered and considered as the promising succinic acid-producing bacteria in many reports. The promoters mentioned above could also be induced by lactose, which had not been attempted for succinic acid production before. Here, the efficient utilization of lactose as inducer was demonstrated in cultures of the ptsG, ldhA, and pflB mutant strain DC1515 with ppc overexpression. A fermentative process for succinic acid production at high level by this strain was developed. In flask anaerobic culture, 14.86 g l(-1) succinic acid was produced from 15 g l(-1) glucose with a yield of 1.51 mol mol(-1) glucose. In two-stage culture carried out in a 3-l bioreactor, the overall yield and concentration of succinic acid reached to 1.67 mol mol(-1) glucose and 99.7 g l(-1), respectively, with a productivity of 1.7 g l(-1) h(-1) in the anaerobic stage. The efficient utilization of lactose as inducer made recombinant E. coli a more capable strain for succinic acid production at large scale.
Wang
Dan
D
Institute of Process Engineering, Chinese Academy of Sciences, Haidian District, Beijing, People's Republic of China.
Li
Qiang
Q
Mao
Yu
Y
Xing
Jianmin
J
Su
Zhiguo
Z
D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D007785:Lactose / Q000378:metabolism*; D009154:Mutation; D010730:Phosphoenolpyruvate Carboxylase / Q000235:genetics* / Q000378:metabolism; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics* / Q000378:metabolism; D019802:Succinic Acid / Q000378:metabolism*
D029968:Escherichia coli Proteins; D019802:Succinic Acid; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C031629:phosphoenolpyruvate-glucose phosphotransferase; D010730:Phosphoenolpyruvate Carboxylase; D007785:Lactose