Very High Thermotolerance of an Adaptive Evolved Saccharomyces cerevisiae in Cellulosic Ethanol Fermentation

High thermotolerance is an important property of Saccharomyces cerevisiae for stable and efficient bioethanol production, especially large-scale production with weak heat transfer the simultaneous saccharification fermentation (SSF) lignocellulosic biomass at high temperatures (above 40 °C). Despite extensive studies involving metabolic engineering chemical mutagenesis, improvement in S. under harsh thermal stress (42–45 °C) has been limited. A highly thermotolerant strain, Z100, by a 91 days’ laboratory adaptive evolution wheat straw hydrolysate was applied cellulosic ethanol fermentation. The results showed that cell survival ratio Z100 50 °C improved 1.2 times parental strain. found to contribute significantly enhanced fermentability. increased 35%, 127%, 64% when using as feedstock after being maintained 12 h, 24 48 respectively. Transcriptome analyses suggested trehalose glycogen synthesis, well carbon metabolism, potentially contributed fermentability Z100. This study provides evidence effective method increasing strain production.