title: Simultaneous saccharification and co-fermentation (SSCF) of AFEX(TM) pretreated corn stover for ethanol production using commercial enzymes and Saccharomyces cerevisiae 424A(LNH-ST).
abstract: Xylose consumption by Saccharomyces cerevisiae 424A(LNH-ST) during simultaneous saccharification and co-fermentation (SSCF) of AFEX(TM) pretreated switchgrass was inhibited by unhydrolyzed solids. Such inhibitory effects were not found in unhydrolyzed solids from AFEX(TM) pretreated corn stover (AFEX(TM)-CS). However, the xylose consumption was still unsatisfactory during 6h pre-hydrolysis SSCF. By extending the pre-hydrolysis time to 24h or longer, the xylose consumption was improved significantly. In order to better understand the reasons for such improvement, the hydrolysate slurries after 6h pre-hydrolysis and 24h pre-hydrolysis were studied and compared. We found that the glucose concentration after pre-hydrolysis was the critical factor that determined cell viability and hence xylose consumption during SSCF. Low temperature (30°C) and ethanol inhibition were shown to be the factors limiting hydrolysis rate and hence productivity during SSCF.
authors.affiliation: Biomass Conversion Research Laboratory (BCRL), Department of Chemical Engineering and Materials Science, Michigan State University, University Corporate Research Complex, 3815 Technology Boulevard, Lansing, MI 48910, USA. jinmingj@egr.msu.edu
authors.forename: Mingjie
authors.initials: M
authors.lastname: Jin
authors.forename: Christa
authors.initials: C
authors.lastname: Gunawan
authors.forename: Venkatesh
authors.initials: V
authors.lastname: Balan
authors.forename: Ming W
authors.initials: MW
authors.lastname: Lau
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Dale
mesh_terms: D002241:Carbohydrates / Q000737:chemistry*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D006868:Hydrolysis; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D003313:Zea mays
chemical_list: D002241:Carbohydrates; D000431:Ethanol