文献类型：期刊文献

英文题名：Systematic manipulation of glutathione metabolism in Escherichia coli for improved glutathione production

作者：Zhang, Jing[1];Quan, Cong[1];Wang, Cheng[1];Wu, Hui[1];Li, Zhimin[1,2];Ye, Qin[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]Shanghai Collaborat Innovat Ctr Biomfg Technol, 130 Meilong Rd, Shanghai 200237, Peoples R China

年份：2016

卷号：15

外文期刊名：MICROBIAL CELL FACTORIES

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000370226300001)】；

基金：This study was supported by the National Science Foundation for Young Scientist of China (Grant No. 21406065), the National High Technology Research and Development Program of China (Grant Nos. 2012AA022104 and 2012AA021205), the Fundamental Research Funds for the Central Universities (Grant Nos. 222201313007 and 22A201514042), the National Special Fund for State Key Laboratory of Bioreactor Engineering (No. 2060204) and Shanghai Committee of Science and Technology (Grant No. 13DZ1930202).

语种：英文

外文关键词：Escherichia coli; Glutathione; Systematic manipulation; Bifunctional glutathione synthetase; Fed-batch fermentation

摘要：Background: l-glutathione (GSH) is a non-protein thiol compound with important biological properties and is widely used in pharmaceutical, food, cosmetic and health products. The cellular GSH is determined by the activity and characteristic of GSH-synthesizing enzymes, energy and precursor supply, and degradation of formed GSH. Results: In this study, genes encoding enzymes related to the precursor amino acid degradation and glycogen formation as well as GSH degradation were systematically manipulated in Escherichia coli strains over-expressing gshF from Actinobacillus succinogenes. The manipulation included disrupting the precursor degradation pathways (tnaA and sdaA), eliminating l-glutathione degradation (ggt and pepT), and manipulating the intracellular ATP level (disruption of glgB). However the constructed mutants showed lower levels of GshF expression. 2-D electrophoresis was performed to elucidate the reasons for this discrepancy, and the results indicated obvious changes in central metabolism and amino acid metabolism in the penta-mutant. Fed-batch culture of the penta-mutant ZJ12345 was performed where the GshF expression level was enhanced, and both the GSH production (19.10 mM) and the yield based on added l-cysteine (0.76 mmol/mmol) were significantly increased. Conclusion: By interrupting the degradation pathways of l-cysteine, serine and GSH and blocking glycogen formation, the GSH production efficiency was significantly improved.