文献类型：期刊文献

英文题名：Enhanced anaerobic succinic acid production by Escherichia coli NZN111 aerobically grown on gluconeogenic carbon sources

作者：Wu, Hui[1];Li, Zhi-Min[1];Zhou, Li[1];Xie, Jingli[1];Ye, Qin[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China

年份：2009

卷号：44

期号：3

起止页码：165

外文期刊名：ENZYME AND MICROBIAL TECHNOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000263209200008)】；

基金：We thank Professor David P. Clark for kindly providing us with the strain E. coli NZN111. This work was supported by the National Natural Science Foundation of China (No. 20576032), and partially supported by the project of Shanghai Leading Academic Disciplines (No. B505).

语种：英文

外文关键词：Succinic acid; Escherichia coli; Glyconeogenic carbon source; Metabolic regulation

摘要：Escherichia coli strain NZN111, a pflB and ldhA double mutant of L coli W1485, is considered a candidate of succinic acid producer. However, it is reported that this strain fails to ferment glucose anaerobically. In this study, it was demonstrated that when a gluconeogenic carbon source was used to replace glucose in aerobic culture, the NZN111 cells restored the ability to ferment glucose in the subsequent anaerobic culture with succinic acid as the major product even though no further genetic manipulation had been carried out. Activities of enzymes including phosphoenolpyruvate (PEP) carboxykinase, PEP carboxylase, isocitrate lyase, malate dehydrogenase, malic enzyme, and pyruvate kinase in the NZN111 cells aerobically grown on different carbon sources were measured, and enhanced anaplerotic and oxaloacetate-reducing activities were revealed. Furthermore, supply Of MgCO3 or NaHCO3 greatly improved succinate production by the malate-grown NZN111 cells. At the same time, pyruvic acid production was significantly reduced. When the malate-grown cells were anaerobically cultured in a salt medium with high pH buffering capacity, succinic acid was produced at a specific productivity of 308 mg/(g DCW h) with a molar yield of 1.31 mol succinic acid/mol glucose. (C) 2008 Elsevier Inc. All rights reserved.