title: Enhanced ethanol fermentation by engineered Saccharomyces cerevisiae strains with high spermidine contents.
abstract: Construction of robust and efficient yeast strains is a prerequisite for commercializing a biofuel production process. We have demonstrated that high intracellular spermidine (SPD) contents in Saccharomyces cerevisiae can lead to improved tolerance against various fermentation inhibitors, including furan derivatives and acetic acid. In this study, we examined the potential applicability of the S. cerevisiae strains with high SPD contents under two cases of ethanol fermentation: glucose fermentation in repeated-batch fermentations and xylose fermentation in the presence of fermentation inhibitors. During the sixteen times of repeated-batch fermentations using glucose as a sole carbon source, the S. cerevisiae strains with high SPD contents maintained higher cell viability and ethanol productivities than a control strain with lower SPD contents. Specifically, at the sixteenth fermentation, the ethanol productivity of a S. cerevisiae strain with twofold higher SPD content was 31% higher than that of the control strain. When the SPD content was elevated in an engineered S. cerevisiae capable of fermenting xylose, the resulting S. cerevisiae strain exhibited much 40-50% higher ethanol productivities than the control strain during the fermentations of synthetic hydrolysate containing high concentrations of fermentation inhibitors. These results suggest that the strain engineering strategy to increase SPD content is broadly applicable for engineering yeast strains for robust and efficient production of ethanol.
authors.affiliation: Department of Agricultural Biotechnology and Center for Food and Bioconvergence, Seoul National University, Seoul, 151-921, Korea.
authors.forename: Sun-Ki
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Department of Agricultural Biotechnology and Center for Food and Bioconvergence, Seoul National University, Seoul, 151-921, Korea.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Jo
authors.affiliation: Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.|Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Yong-Su
authors.initials: YS
authors.lastname: Jin
authors.affiliation: Department of Agricultural Biotechnology and Center for Food and Bioconvergence, Seoul National University, Seoul, 151-921, Korea. jhseo94@snu.ac.kr.
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Seo
mesh_terms: D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D060847:Metabolic Engineering; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D013095:Spermidine / Q000378:metabolism*; D014994:Xylose / Q000378:metabolism
chemical_list: D000431:Ethanol; D014994:Xylose; D005947:Glucose; D013095:Spermidine
keywords: Biofuels; Inhibitor tolerance; Repeated-batch fermentation; Spermidine; Xylose