title: Comparison of process configurations for ethanol production from acid- and alkali-pretreated corncob by Saccharomyces cerevisiae strains with and without β-glucosidase expression.
abstract: β-Glucosidase was shown to have synergistic effects with commercial cellulase in the hydrolysis of acid- and alkali-pretreated corncob, especially at the dose of 5 U/g biomass and 5 or 10 FPU/g biomass. An integrating yeast strain 45# expressing β-glucosidase was constructed that utilized cellobiose quickly and efficiently. Process configurations were compared under conditions of 10% solid content, 10 FPU cellulase/g biomass, 5 U β-glucosidase/g biomass (only used for parental strain W303-1A), 1g/kg yeast loading and 3.3g/kg urea supplementation. While separate hydrolysis and fermentation was optimal for W303-1A and the ethanol titer and yield reached 3.22 g/100g and 75.6% (expressed as a percentage of the theoretical yield), respectively, simultaneous saccharification and fermentation was optimal for strain 45# and the ethanol titer and yield reached 3.31 g/100g and 77.7%, respectively. These results are valuable in optimization of the process configuration and improving the yeast strain selected for cellulosic ethanol production.
authors.affiliation: Tianjin R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Wang
authors.forename: Cheng
authors.initials: C
authors.lastname: Liu
authors.forename: Jiefang
authors.initials: J
authors.lastname: Hong
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Ma
authors.forename: Kun
authors.initials: K
authors.lastname: Zhang
authors.forename: Xinyu
authors.initials: X
authors.lastname: Huang
authors.forename: Shaolan
authors.initials: S
authors.lastname: Zou
authors.forename: Minhua
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000143:Acids / Q000737:chemistry*; D000468:Alkalies / Q000737:chemistry*; D000431:Ethanol / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000378:metabolism*; D003313:Zea mays; D001617:beta-Glucosidase / Q000378:metabolism*
chemical_list: D000143:Acids; D000468:Alkalies; D000431:Ethanol; D001617:beta-Glucosidase
keywords: Cellulosic ethanol; Process configuration; Recombinant yeast; Synergy; β-Glucosidase