Overexpression of RCK1 improves acetic acid tolerance in Saccharomyces cerevisiae

Journal Article · 03 January 2019 · Journal of Biotechnology

DOI: https://doi.org/10.1016/j.jbiotec.2018.12.013 · OSTI ID:1991851

Oh, Eun Joong ^[1]; Wei, Na ^[2]; Kwak, Suryang ^[3]; Kim, Heejin ^[3]; Jin, Yong-Su ^[3]

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1. University of Illinois at Urbana-Champaign, IL (United States); UIUC
2. University of Notre Dame, IN (United States)
3. University of Illinois at Urbana-Champaign, IL (United States)

Mixed sugars derived from lignocellulosic biomass can be converted into biofuels and chemicals by engineered microorganisms, but toxic fermentation inhibitors produced from harsh depolymerization processes of lignocellulosic biomass pose a critical challenge for economic production of biofuels and chemicals. Unlike other fermentation inhibitors generated from sugar degradation, acetic acid is inevitably produced from acetylated hemicellulose, and its concentrations in cellulosic hydrolysates are substantially higher than other fermentation inhibitors. Furthermore, the aim of this study was to identify novel genetic perturbations for improved acetic acid tolerance in Saccharomyces cerevisiae. Through a genomic library-based approach, we identified an overexpression gene target RCK1 coding for a protein kinase involved in oxidative stress. Overexpression of RCK1 significantly improved glucose and xylose fermentation under acetic acid stress conditions. Specifically, the RCK1-overexpressing strain exhibited a two-fold higher specific ethanol productivity than the control strain in glucose fermentation under the presence of acetic acid. Interestingly, the engineered S. cerevisiae overexpressing RCK1 showed 40% lower intracellular reactive oxygen species (ROS) levels as compared to the parental strain when the strains were exposed to acetic acid, suggesting that RCK1 overexpression might play a role in reducing the oxidative stress caused by acetic acid.

• Research Organization: Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), Urbana, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Grant/Contract Number: SC0018420
• OSTI ID: 1991851
• Journal Information: Journal of Biotechnology, Journal Name: Journal of Biotechnology Vol. 292; ISSN 0168-1656
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English