Altered sterol composition renders yeast thermotolerant

• DOI: 10.1126/science.1258137
• Publication Date: 2014-10-02T21:43:10Z
• Authors: Luis Caspeta; Yun Chen; Payam Ghiaci; Amir Feizi; Steen Buskov; Björn M. Hallström; Dina Petranovic; Jens Nielsen
• Keywords: 0301 basic medicine; 03 medical and health sciences

Ethanol production for use as a biofuel is mainly achieved through simultaneous saccharification and fermentation by yeast. Operating at ≥40°C would be beneficial in terms of increasing efficiency the process reducing costs, but yeast does not grow efficiently those temperatures. We used adaptive laboratory evolution to select strains with improved growth ethanol ≥40°C. Sequencing whole genome, genome-wide gene expression, metabolic-flux analyses revealed change sterol composition, from ergosterol fecosterol, caused mutations C-5 desaturase gene, increased expression genes involved biosynthesis. Additionally, large chromosome III rearrangements associated DNA damage respiration were found, contributed less thermotolerant phenotype.