title: Pyruvate decarboxylase and alcohol dehydrogenase overexpression in Escherichia coli resulted in high ethanol production and rewired metabolic enzyme networks.
abstract: Pyruvate decarboxylase and alcohol dehydrogenase are efficient enzymes for ethanol production in Zymomonas mobilis. These two enzymes were over-expressed in Escherichia coli, a promising candidate for industrial ethanol production, resulting in high ethanol production in the engineered E. coli. To investigate the intracellular changes to the enzyme overexpression for homoethanol production, 2-DE and LC-MS/MS were performed. More than 1,000 protein spots were reproducibly detected in the gel by image analysis. Compared to the wild-type, 99 protein spots showed significant changes in abundance in the recombinant E. coli, in which 46 were down-regulated and 53 were up-regulated. Most proteins related to tricarboxylic acid cycle, glycerol metabolism and other energy metabolism were up-regulated, whereas proteins involved in glycolysis and glyoxylate pathway were down-regulated, indicating the rewired metabolism in the engineered E. coli. As glycolysis is the main pathway for ethanol production, and it was inhibited significantly in engineered E. coli, further efforts should be directed at minimizing the repression of glycolysis to optimize metabolism network for higher yields of ethanol production.
authors.affiliation: Key Laboratory of Urban Agriculture (North) Ministry of Agriculture, Beijing University of Agriculture, Beijing, 102206, China.
authors.forename: Mingfeng
authors.initials: M
authors.lastname: Yang
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Li
authors.forename: Chunya
authors.initials: C
authors.lastname: Bu
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Guanglu
authors.initials: G
authors.lastname: Shi
authors.forename: Xiushan
authors.initials: X
authors.lastname: Yang
authors.forename: Yong
authors.initials: Y
authors.lastname: Hu
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Wang
mesh_terms: D000426:Alcohol Dehydrogenase / Q000096:biosynthesis* / Q000235:genetics; D002853:Chromatography, Liquid; D003001:Cloning, Molecular; D015180:Electrophoresis, Gel, Two-Dimensional; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D015870:Gene Expression; D053263:Gene Regulatory Networks; D060847:Metabolic Engineering; D053858:Metabolic Networks and Pathways; D011767:Pyruvate Decarboxylase / Q000096:biosynthesis* / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D053719:Tandem Mass Spectrometry; D017355:Zymomonas / Q000201:enzymology / Q000235:genetics
chemical_list: D011994:Recombinant Proteins; D000431:Ethanol; D000426:Alcohol Dehydrogenase; D011767:Pyruvate Decarboxylase