Chemical genomic guided engineering of gamma-valerolactone tolerant yeast

作者：Scott Bottoms, Quinn Dickinson, Mick McGee, Li Hinchman, Alan Higbee, Alex S. Hebert, José Serate, Dan Xie, Yaoping Zhang, Joshua J. Coon, Chad L. Myers, Robert Landick, Jeff S. Piotrowski · 发表于：Microbial Cell Factories · 年份：2018 · DOI：10.1186/s12934-017-0848-9 · 被引用次数：15 · 研究领域：Biofuel production and bioconversion、Microbial Metabolic Engineering and Bioproduction、Fungal and yeast genetics research

BACKGROUND: Gamma valerolactone (GVL) treatment of lignocellulosic bomass is a promising technology for degradation of biomass for biofuel production; however, GVL is toxic to fermentative microbes. Using a combination of chemical genomics with the yeast (Saccharomyces cerevisiae) deletion collection to identify sensitive and resistant mutants, and chemical proteomics to monitor protein abundance in the presence of GVL, we sought to understand the mechanism toxicity and resistance to GVL with the goal of engineering a GVL-tolerant, xylose-fermenting yeast. RESULTS: Chemical genomic profiling of GVL predicted that this chemical affects membranes and membrane-bound processes. We show that GVL causes rapid, dose-dependent cell permeability, and is synergistic with ethanol. Chemical genomic profiling of GVL revealed that deletion of the functionally related enzymes Pad1p and Fdc1p, which act together to decarboxylate cinnamic acid and its derivatives to vinyl forms, increases yeast tolerance to GVL. Further, overexpression of Pad1p sensitizes cells to GVL toxicity. To improve GVL tolerance, we deleted PAD1 and FDC1 in a xylose-fermenting yeast strain. The modified strain exhibited increased anaerobic growth, sugar utilization, and ethanol production in synthetic hydrolysate with 1.5% GVL, and under other conditions. Chemical proteomic profiling of the engineered strain revealed that enzymes involved in ergosterol biosynthesis were more abundant in the presence of GVL compared to ...