Molecular mechanism of the improved thermotolerance and the facilitated ethanol fermentability in the evolved Saccharomyces cerevisiae

Thermotolerance development of robust Saccharomyces cerevisiae is necessary to enhance enzyme activity of cellulase, lower cooling costs, and reduce cell harm from the bad-distributed heat transfer in large-scale fermentation. The process-based studies of adaptive evolution have been well documented, but it remains unknown for the underlying molecular mechanism of the improved thermotolerance and the facilitated ethanol fermentability derived from adaptive evolution. Genome requencing was used to investigate the molecular mechanism for the evolved S. cerevisiae. It proved that the outstanding thermotolerance performance of the evolved strain brought about less single-nucleotide polymorphisms (SNPs) through genome resequencing. The key mutation derived from adaptive evolution would provide a robust thermotolerant S. cerevisiae for bioethanol production and an important clue for future synthetic biology to thermotolerance engineering of fermentation strains.