文献类型：期刊文献

英文题名：Utilization of excess NADH in 2,3-butanediol-deficient Klebsiella pneumoniae for 1,3-propanediol production

作者：Cui, Y. L.[1];Zhou, J. J.[1];Gao, L. R.[1];Zhu, C. Q.[1];Jiang, X.[1];Fu, S. L.[1];Gong, H.[1]

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

年份：2014

卷号：117

期号：3

起止页码：690

外文期刊名：JOURNAL OF APPLIED MICROBIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000342215300009)】；

基金：This work was supported by the National Natural Science Foundation of China under Grant No. 31271862.

语种：英文

外文关键词：1,3-propanediol; 2,3-butanediol; dhaT overexpression; Klebsiella pneumoniae; lactate; NADH

摘要：Aims: To utilize excess NADH for 1,3-propanediol production by 2, 3-butanediol-deficient mutants, the effect of dhaT overexpression in two distinct 2,3-butanediol-deficient mutants was investigated. Methods and Results: Two 2,3-butanediol-deficient mutants, KG1-3 (blocking of the 2,3-butanediol pathway only) and KG1-5 (blocking of both of 2,3-butanediol and lactate pathways) were constructed. Our results showed that although the intracellular redox balance (NADH/NAD(+)) was extremely high at the end of fermentation for both mutants, the status of intracellular redox in KG1-5 was maintained at a normal level following the first stage of fermentation. Analysis of cell growth and metabolite formation confirmed the inhibition of excess lactate in 2,3-butanediol pathway-deficient mutants. Furthermore, dhaT was overexpressed in two 2,3-butanediol-deficient mutants (KG1-3T and KG1-5T). In KG1-5T, the intracellular redox balance was restored to normal and 1,3-propanediol production increased. The yield of 1,3-propanediol from glycerol in KG1-5T was also restored to a normal level of 0.6. Conclusions: The excess NADH in both the 2,3-butanediol-and lactate-deficient mutants can be used by overexpresstion of dhaT. Significance and Impact of Study: The metabolic flux tended to increase lactate production by the abolishment of the 2,3-butanediol pathway in Klebsiella pneumoniae, and the high accumulation of lactate prevented the cell from using excess NADH, thereby inhibiting cell growth and 1,3-propanediol production.