title: Comparison of xylose fermentation by two high-performance engineered strains ofSaccharomyces cerevisiae.
abstract: Economical biofuel production from plant biomass requires the conversion of both cellulose and hemicellulose in the plant cell wall. The best industrial fermentation organism, the yeastSaccharomyces cerevisiae,has been developed to utilize xylose by heterologously expressing either a xylose reductase/xylitol dehydrogenase (XR/XDH) pathway or a xylose isomerase (XI) pathway. Although it has been proposed that the optimal means for fermenting xylose into biofuels would use XI instead of the XR/XDH pathway, no clear comparison of the best publicly-available yeast strains engineered to use XR/XDH or XI has been published. We therefore compared two of the best-performing engineered yeast strains in the public domain-one using the XR/XDH pathway and another using XI-in anaerobic xylose fermentations. We find that, regardless of conditions, the strain using XR/XDH has substantially higher productivity compared to the XI strain. By contrast, the XI strain has better yields in nearly all conditions tested.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Annsea
authors.initials: A
authors.lastname: Park
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Raissa
authors.initials: R
authors.lastname: Estrela
authors.affiliation: Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA.
authors.forename: Soo-Rin
authors.initials: SR
authors.lastname: Kim
authors.affiliation: Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA; Department of Food and Science and Human Nutrition, University of Illinois, Urbana, IL 61801, USA.
authors.forename: Yong-Su
authors.initials: YS
authors.lastname: Jin
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA; Department of Chemistry, University of California, Berkeley, CA 94720, USA; Physical Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
authors.forename: Jamie H D
authors.initials: JH
authors.lastname: Cate
keywords: Biofuels; Fermentation; Xylitol dehydrogenase; Xylose; Xylose isomerase; Xylose reductase