title: Transcriptional analysis of micronutrient zinc-associated response for enhanced carbohydrate utilization and earlier solventogenesis in Clostridium acetobutylicum.
abstract: The micronutrient zinc plays vital roles in ABE fermentation by Clostridium acetobutylicum. In order to elucidate the zinc-associated response for enhanced glucose utilization and earlier solventogenesis, transcriptional analysis was performed on cells grown in glucose medium at the exponential growth phase of 16 h without/with supplementary zinc. Correspondingly, the gene glcG (CAC0570) encoding a glucose-specific PTS was significantly upregulated accompanied with the other two genes CAC1353 and CAC1354 for glucose transport in the presence of zinc. Additionally, genes involved in the metabolisms of six other carbohydrates (maltose, cellobiose, fructose, mannose, xylose and arabinose) were differentially expressed, indicating that the regulatory effect of micronutrient zinc is carbohydrate-specific with respects to the improved/inhibited carbohydrate utilization. More importantly, multiple genes responsible for glycolysis (glcK and pykA), acidogenesis (thlA, crt, etfA, etfB and bcd) and solventogenesis (ctfB and bdhA) of C. acetobutylicum prominently responded to the supplementary zinc at differential expression levels. Comparative analysis of intracellular metabolites revealed that the branch node intermediates such as acetyl-CoA, acetoacetyl-CoA, butyl-CoA, and reducing power NADH remained relatively lower whereas more ATP was generated due to enhanced glycolysis pathway and earlier initiation of solventogenesis, suggesting that the micronutrient zinc-associated response for the selected intracellular metabolisms is significantly pleiotropic.
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China.
authors.forename: You-Duo
authors.initials: YD
authors.lastname: Wu
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Chuang
authors.initials: C
authors.lastname: Xue
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Li-Jie
authors.initials: LJ
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, Liaoning, China.
authors.forename: Hui-Hui
authors.initials: HH
authors.lastname: Wan
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China.|School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Feng-Wu
authors.initials: FW
authors.lastname: Bai
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D056804:Biofuels; D000440:Butanols / Q000378:metabolism*; D002853:Chromatography, Liquid; D046969:Clostridium acetobutylicum / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D004187:Disaccharides / Q000378:metabolism; D005285:Fermentation / Q000187:drug effects / Q000235:genetics; D020869:Gene Expression Profiling / Q000379:methods*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis / Q000235:genetics; D009005:Monosaccharides / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012997:Solvents / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D015032:Zinc / Q000494:pharmacology*
chemical_list: D001426:Bacterial Proteins; D056804:Biofuels; D000440:Butanols; D004187:Disaccharides; D009005:Monosaccharides; D011134:Polysaccharides; D012997:Solvents; D005947:Glucose; D015032:Zinc