Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6491336 | Journal of Biotechnology | 2014 | 7 Pages |
Abstract
In order to redirect more carbon flux from TCA cycle into poly(3-hydroxybutyrate) (PHB) biosynthesis pathway via increasing respiratory efficiency, appB and ndh genes encoding cytochrome bd-II oxidase and NDH-II dehydrogenase were inactivated in Escherichia coli JM109/pBHR68. All appB or/and ndh knockout strains exhibited significantly increased PHB accumulation accompanying with increased NAD(P)H/NAD(P)+ ratio and intracellular acetyl-CoA pool. Among them, the Îndh strain could accumulate up to 6.16Â g/L PHB from 20Â g/L glucose and 3.5Â g/L PHB from 20Â g/L xylose, respectively, a 1.76-fold and 3.43-fold increase compared to the wild-type control. The PHB production of this strain reached 28.23Â g/L in a 5-L fermentor study, which was 2.70-fold as much as that of the wild-type control. These results indicated that inactivating the cytochrome bd-II oxidase or/and NDH-II dehydrogenase of the aerobic respiratory chain is a simple and effective strategy to improve PHB biosynthesis in E. coli. To date, this is the first time to improve PHB production by inactivation of cytochrome bd-II oxidase or/and NDH-II dehydrogenase in low efficient respiratory chains.
Related Topics
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Authors
Qiaojie Liu, Zhenquan Lin, Yan Zhang, Yifan Li, Zhiwen Wang, Tao Chen,