title: Co-solvent pretreatment reduces costly enzyme requirements for high sugar and ethanol yields from lignocellulosic biomass.
abstract: We introduce a new pretreatment called co-solvent-enhanced lignocellulosic fractionation (CELF) to reduce enzyme costs dramatically for high sugar yields from hemicellulose and cellulose, which is essential for the low-cost conversion of biomass to fuels. CELF employs THF miscible with aqueous dilute acid to obtain up to 95 % theoretical yield of glucose, xylose, and arabinose from corn stover even if coupled with enzymatic hydrolysis at only 2 mgenzyme  gglucan (-1) . The unusually high saccharification with such low enzyme loadings can be attributed to a very high lignin removal, which is supported by compositional analysis, fractal kinetic modeling, and SEM imaging. Subsequently, nearly pure lignin product can be precipitated by the evaporation of volatile THF for recovery and recycling. Simultaneous saccharification and fermentation of CELF-pretreated solids with low enzyme loadings and Saccharomyces cerevisiae produced twice as much ethanol as that from dilute-acid-pretreated solids if both were optimized for corn stover.
authors: Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, 1084 Columbia Avenue, Riverside, California 92507 (USA), Fax: (+1) 951-781-5790.|Department of Bioengineering, Bourns College of Engineering, University of California, Riverside, 217 Materials Science & Engineering, 900 University Ave., Riverside, CA 92507 (USA).
authors: Thanh Yen
authors: TY
authors: Nguyen
authors: Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, 1084 Columbia Avenue, Riverside, California 92507 (USA), Fax: (+1) 951-781-5790.|Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, 446 Winston Chung Hall, 900 University Ave., Riverside, CA 92507 (United States).|BioEnergy Science Center (BESC), Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (USA).
authors: Charles M
authors: CM
authors: Cai
authors: Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, 1084 Columbia Avenue, Riverside, California 92507 (USA), Fax: (+1) 951-781-5790.|BioEnergy Science Center (BESC), Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (USA).
authors: Rajeev
authors: R
authors: Kumar
authors: Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, 1084 Columbia Avenue, Riverside, California 92507 (USA), Fax: (+1) 951-781-5790. cewyman@engr.ucr.edu.|Department of Bioengineering, Bourns College of Engineering, University of California, Riverside, 217 Materials Science & Engineering, 900 University Ave., Riverside, CA 92507 (USA). cewyman@engr.ucr.edu.|Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, 446 Winston Chung Hall, 900 University Ave., Riverside, CA 92507 (United States). cewyman@engr.ucr.edu.|BioEnergy Science Center (BESC), Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (USA). cewyman@engr.ucr.edu.
authors: Charles E
authors: CE
authors: Wyman
mesh_terms: D001089:Arabinose / Q000737:chemistry; D018533:Biomass; D002480:Cellulase / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry / Q000378:metabolism; D005285:Fermentation; D005947:Glucose / Q000737:chemistry; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D012997:Solvents / Q000737:chemistry; D014994:Xylose / Q000737:chemistry; D003313:Zea mays
chemical_list: D012997:Solvents; C036909:lignocellulose; D000431:Ethanol; D008031:Lignin; D014994:Xylose; D001089:Arabinose; D002480:Cellulase; D005947:Glucose
keywords: biomass; enzymes; hydrolysis; renewable resources; solvent effects