Improving multiple stress-tolerance of a flocculating industrial Saccharomyces cerevisiae strain by random mutagenesis and hybridization

• Published in: Process biochemistry (1991) 2021-03, Vol.102, p.275-285
• Main Authors: Wang, Li, Li, Bo, Wang, Shi-Peng, Xia, Zi-Yuan, Gou, Min, Tang, Yue-Qin
• Format: Article
• Language: English
• Subjects: Antioxidants; ARTP mutagenesis; Biofuels; Breeding; Catalase; Ethanol; Ethanol fermentation; Fermentation; Flocculation; Fungi; Genome shuffling; Genomes; High temperature; Hybridization; Multiple stress-tolerance; Mutagenesis; Osmosis; Random mutagenesis; Reactive oxygen species; Room temperature; Saccharomyces cerevisiae; Strain; Stress; Superoxide dismutase; Temperature tolerance; Very high gravity fermentation; Yeast
• ISSN: 1359-5113; 1873-3298
• DOI: 10.1016/j.procbio.2020.12.022

[Display omitted] •A novel strategy was proposed to breed multiple stress-tolerant strain E-158.•Ethanol production was significantly improved under different stress conditions.•Good genetic stability of E-158 was found after 30 times of sub-cultivation.•Strain E-158 had strong antioxidant defense ability. Breeding stress-tolerant industrial Saccharomyces cerevisiae strains is crucial to reduce the cost of bioethanol production. In this study, a novel strategy, atmospheric and room temperature plasma (ARTP) mutagenesis combined with genome shuffling and hybridization, was successfully applied to obtain a multiple stress-tolerant flocculating industrial S. cerevisiae strain E-158. The enhanced strain E-158 grew better under various stress conditions compared with the original strain KF-7. The concentrations of ethanol produced by strain E-158 during batch fermentation were 10.14 %–81.02 % higher than those produced by strain KF-7 under high ethanol, high temperature, and high osmosis stress conditions. The stress tolerance of E-158 kept stable even after 30 times of sub-cultivation. The lower reactive oxygen species (ROS) level and higher superoxide dismutase (SOD) and catalase (CAT) activities in strain E-158 manifested that the antioxidant defense ability of E-158 was improved and contributed to its multiple stress-tolerance. This study provided a stress-tolerant strain for industrial ethanol production and a feasible strategy for breeding multiple stress-tolerant industrial S. cerevisiae strain.