Physiological and Molecular Characterization of an Oxidative Stress-Resistant Saccharomyces cerevisiae Strain Obtained by Evolutionary Engineering

Oxidative stress is a major game-changer in industrial applications due to its direct impact on cell growth, viability, and productivity. Currently, little information is available regarding the molecular mechanisms of oxidative stress induction and antioxidant response to elevated reactive oxygen species (ROS) in industrial yeast application. In this study, we employed adaptive laboratory evolution strategies to obtain a genetically stable oxidative stress-resistant S. cerevisiae strain. This evolved strain has eminent trehalose and glycogen production, with up-regulated gene expression profile related to stress response, transport, carbohydrate, lipid and co-factor metabolic processes, protein phosphorylation, cell wall organization or biogenesis. In addition, comparative physiological analyses revealed that this mutant is also cross-resistant to other stress types including heat, freeze-thaw, ethanol, copper, and salt stress. It also contains single variants primarily related to stress response, cell wall organization, carbohydrate metabolism/transport in line with findings of physiological and transcriptomic results. These characteristics may shed light on how oxidative stress resistant S. cerevisiae strain can cope with selective oxidative stress pressure using its complex molecular mechanisms.