title: Combined overexpression of genes involved in pentose phosphate pathway enables enhanced D-xylose utilization by Clostridium acetobutylicum.
abstract: D-Xylose utilization by Clostridium acetobutylicum, an important industrial microorganism used in ABE (Acetone, Butanol and Ethanol) production, has attracted increasing interests. We demonstrated previously that co-overexpression of genes, encoding d-xylose symporter, D-xylose isomerase and xylulokinase, improved D-xylose utilization by C. acetobutylicum (Xiao, H., et al., 2011. Applied and Environmental Microbiology 77, 7886-7895). Here, we further identified genes involved in PPP (Pentose Phosphate Pathway) in C. acetobutylicum and evaluated their contribution to d-xylose utilization. Among all the candidate genes, the CAC1347, CAC1348, CAC1730 and CAC2880 were validated to encode genes tal, tkl, rpe and rpi, four key genes involved in PPP, respectively. The following combined overexpression of these genes conferred a significantly improved xylose-utilizing ability to the recombinant strain, reaching a solvent titer 42% higher than that of the wild-type strain. This finding offers a useful strategy to optimize d-xylose utilization by C. acetobutylicum.
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Graduate University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Jin
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Graduate University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Hebei Normal University, Hebei 050024, China.
authors.forename: Liwen
authors.initials: L
authors.lastname: Chen
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Yang
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Shanghai Research and Development Center of Industrial Biotechnology, Shanghai 201201, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Yang
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address: whjiang@sibs.ac.cn.
authors.forename: Weihong
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address: ygu02@sibs.ac.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gu
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000235:genetics / Q000378:metabolism; D046969:Clostridium acetobutylicum / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D010427:Pentose Phosphate Pathway; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012997:Solvents; D027981:Symporters / Q000235:genetics / Q000378:metabolism; D014994:Xylose / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D012997:Solvents; D027981:Symporters; D014994:Xylose; D017853:Phosphotransferases (Alcohol Group Acceptor); C032700:xylulokinase; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase
keywords: C. acetobutylicum; Genes involved in PPP; d-Xylose utilization