Crabtree/Warburg-like aerobic xylose fermentation by engineered Saccharomyces cerevisiae.

Autor: Lee SB; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, WI, USA; Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, WI, USA; Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, USA; Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI, USA., Tremaine M; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, WI, USA., Place M; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, WI, USA; Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, USA; Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI, USA., Liu L; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, WI, USA., Pier A; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, WI, USA., Krause DJ; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, WI, USA; Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, WI, USA; Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, USA; Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI, USA., Xie D; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, WI, USA., Zhang Y; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, WI, USA., Landick R; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, WI, USA; Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA; Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA., Gasch AP; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, WI, USA; Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, USA; Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI, USA., Hittinger CT; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, WI, USA; Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, WI, USA; Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, USA; Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI, USA. Electronic address: cthittinger@wisc.edu., Sato TK; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, WI, USA. Electronic address: tksato@glbrc.wisc.edu.
Jazyk: angličtina
Zdroj: Metabolic engineering [Metab Eng] 2021 Nov; Vol. 68, pp. 119-130. Date of Electronic Publication: 2021 Sep 27.
DOI: 10.1016/j.ymben.2021.09.008
Abstrakt: Bottlenecks in the efficient conversion of xylose into cost-effective biofuels have limited the widespread use of plant lignocellulose as a renewable feedstock. The yeast Saccharomyces cerevisiae ferments glucose into ethanol with such high metabolic flux that it ferments high concentrations of glucose aerobically, a trait called the Crabtree/Warburg Effect. In contrast to glucose, most engineered S. cerevisiae strains do not ferment xylose at economically viable rates and yields, and they require respiration to achieve sufficient xylose metabolic flux and energy return for growth aerobically. Here, we evolved respiration-deficient S. cerevisiae strains that can grow on and ferment xylose to ethanol aerobically, a trait analogous to the Crabtree/Warburg Effect for glucose. Through genome sequence comparisons and directed engineering, we determined that duplications of genes encoding engineered xylose metabolism enzymes, as well as TKL1, a gene encoding a transketolase in the pentose phosphate pathway, were the causative genetic changes for the evolved phenotype. Reengineered duplications of these enzymes, in combination with deletion mutations in HOG1, ISU1, GRE3, and IRA2, increased the rates of aerobic and anaerobic xylose fermentation. Importantly, we found that these genetic modifications function in another genetic background and increase the rate and yield of xylose-to-ethanol conversion in industrially relevant switchgrass hydrolysate, indicating that these specific genetic modifications may enable the sustainable production of industrial biofuels from yeast. We propose a model for how key regulatory mutations prime yeast for aerobic xylose fermentation by lowering the threshold for overflow metabolism, allowing mutations to increase xylose flux and to redirect it into fermentation products.
(Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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