title: Metabolic and process engineering of Clostridium cellulovorans for biofuel production from cellulose.
abstract: Production of cellulosic biofuels has drawn increasing attention. However, currently no microorganism can produce biofuels, particularly butanol, directly from cellulosic biomass efficiently. Here we engineered a cellulolytic bacterium, Clostridium cellulovorans, for n-butanol and ethanol production directly from cellulose by introducing an aldehyde/alcohol dehydrogenase (adhE2), which converts butyryl-CoA to n-butanol and acetyl-CoA to ethanol. The engineered strain was able to produce 1.42 g/L n-butanol and 1.60 g/L ethanol directly from cellulose. Moreover, the addition of methyl viologen as an artificial electron carrier shifted the metabolic flux from acid production to alcohol production, resulting in a high biofuel yield of 0.39 g/g from cellulose, comparable to ethanol yield from corn dextrose by yeast fermentation. This study is the first metabolic engineering of C. cellulovorans for n-butanol and ethanol production directly from cellulose with significant titers and yields, providing a promising consolidated bioprocessing (CBP) platform for biofuel production from cellulosic biomass.
authors.affiliation: Department of Chemical and Biomolecular Engineering and Department of Molecular Genetics, The Ohio State University, 151 West Woodruff Avenue, Columbus, OH 43210, USA.
authors.forename: Xiaorui
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Chemical and Biomolecular Engineering and Department of Molecular Genetics, The Ohio State University, 151 West Woodruff Avenue, Columbus, OH 43210, USA.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Xu
authors.affiliation: Department of Chemical and Biomolecular Engineering and Department of Molecular Genetics, The Ohio State University, 151 West Woodruff Avenue, Columbus, OH 43210, USA. Electronic address: yang.15@osu.edu.
authors.forename: Shang-Tian
authors.initials: ST
authors.lastname: Yang
mesh_terms: D000426:Alcohol Dehydrogenase / Q000235:genetics; D000444:Aldehyde Dehydrogenase / Q000235:genetics; D056804:Biofuels; D018533:Biomass; D000440:Butanols / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism*; D046974:Clostridium cellulovorans / Q000235:genetics* / Q000378:metabolism*; D003065:Coenzyme A / Q000378:metabolism; D003470:Culture Media; D000431:Ethanol / Q000378:metabolism; D060847:Metabolic Engineering / Q000379:methods*; D010269:Paraquat / Q000494:pharmacology; D010957:Plasmids
chemical_list: D056804:Biofuels; D000440:Butanols; D003470:Culture Media; D000431:Ethanol; D002482:Cellulose; D000426:Alcohol Dehydrogenase; D000444:Aldehyde Dehydrogenase; D010269:Paraquat; D003065:Coenzyme A
keywords: Biofuel; Butanol; Cellulose; Clostridium cellulovorans; Ethanol; Metabolic engineering