文献类型：期刊文献

英文题名：Insights into 3-hydroxypropionic acid biosynthesis revealed by overexpressing native glycerol dehydrogenase in Klebsiella pneumoniae

作者：Su, Ming-Yue[1]; Li, Ying[1]; Ge, Xi-Zhen[2]; Tian, Ping-Fang[1]

第一作者：Su, Ming-Yue

通讯作者：Tian, Ping-Fang

机构：[1] College of Life Science and Technology, Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing, China; [2] College of Biochemical Engineering, Beijing Union University, Beijing, China

第一机构：College of Life Science and Technology, Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing, China

年份：2014

卷号：28

期号：4

起止页码：762-768

外文期刊名：Biotechnology and Biotechnological Equipment

收录：EI(收录号：20144600194766);Scopus(收录号：2-s2.0-84910052245)

语种：英文

外文关键词：Byproducts - Cell growth - Oxidation - Fermentation - Metabolic engineering - Adenosinetriphosphate - Reaction intermediates - Bacteria - Growth kinetics - Lactic acid - Metabolism

摘要：In Klebsiella pneumoniae, glycerol dissimilation involves parallel oxidation and reduction pathways. Oxidation pathway provides adenosine triphosphate (ATP) and cofactors to sustain cell growth, while reduction pathway presents 3-hydroxypropionic acid (3-HP) and 1,3-propanediol(1,3-PDO), which are commercially attractive platform chemicals. Previous metabolic engineering of K. pneumoniae focused on the intensification of reduction pathway; however, it failed to overproduce 3-HP or 1,3-PDO. Contrary to this strategy, here we show that overexpression of glycerol dehydrogenase (dhaD), the first functional enzyme in oxidation pathway, can efficiently stimulate cell growth and facilitate 3-HP accumulation. Under microaerobic conditions, although metabolic burden arising from plasmid replication, the recombinant K. pneumoniae overexpressing dhaD grew actively and showed 60% enhancement of 3-HP compared to the control. In particular, overexpression of dhaD increased the activity of glycerol dehydratase, indicating the concerted action of two enzymes and the interdependence between glycerol oxidation and reduction pathways. Moreover, the strain overexpressing dhaD produced more lactic acid yet less acetic acid than the control, implying the interplay between dhaD expression and the formation of byproducts. Together, not only showing that intensifying glycerol oxidation pathway is beneficial to 3-HP production, this study also reveals the structural rigidity of dha operon that mediates glycerol dissimilation in K. pneumoniae. ? 2014 The Author(s). Published by Taylor & Francis.