Fermentative production of enantiomerically pure S-1,2-propanediol from glucose by engineered E. coli strain----中国科学院微生物研究所

科研成果

论文题目:	Fermentative production of enantiomerically pure S-1,2-propanediol from glucose by engineered E. coli strain
作者:	Zhu Lingfeng, Guan Xiangchen, Xie Nengzhong, Wang Limin, Yu Bo*, and Ma Yanhe.
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刊物名称:	Appl Microbiol Biotechnol
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年份:	2015
影响因子:	3.848
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摘要:	The pure stereoisomers of 1,2-propanediol (1,2-PDO) could be used as starting materials to synthesize high value-added specialty chemicals and chiral pharmaceutical products. As the stereoisomers of 1,2-PDO cannot be obtained by traditional chemical synthesis processes, biotechnological processes have gained increasing attention. However, to our knowledge, the production of S-1,2-PDO directly from glucose has not been previously reported. In this study, we demonstrate a novel artificial pathway to convert L-lactic acid to S-1,2-PDO and its integration into the genome of Escherichia coli strain BW25113poxB with synchronous deletion of genes responsible for branch metabolic pathways from glucose. L-lactate production was increased by replacing the native D-lactate dehydrogenase with the L-lactate dehydrogenase from Bacillus coagulans. The methylglyoxal bypass pathway was blocked to avoid synthesis of a racemic mixture of D- and L-lactate and prevent the accumulation of methylglyoxal, a toxic intermediate. To further improve the yield of S-1,2-PDO, a novel cofactor regeneration system was introduced by combining pyruvate decarboxylase and acetaldehyde-CoA dehydrogenase II to simultaneously regenerate NADH and the CoA donor of acetyl-CoA for the lactate conversion pathway. Finally, 13.7 mM S-1,2-PDO with >99 % enantiomeric purity was directly produced from glucose by disrupting the major carbon-competing pathways and strengthening the lactate transformation pathway. This study demonstrates the first attempt to synthesize S-1,2-PDO by direct fermentation of glucose.