Isolation and characterization of ethanol-tolerant yeast strains

Biofuels derived from ethanol are used worldwide, driving research efforts to increase ethanol production from sustainable biological sources. In the yeast model Saccharomyces cerevisiae, increased ethanol levels are toxic and can lead to cell death. The goal of this project is to isolate and characterize yeast strains that are resistant to high levels of ethanol. We mutagenized the common lab strain BY4741 using ethyl methanesulfonate (EMS) and then cultured the population in a high-ethanol environment that the parental strain cannot tolerate. Ethanol-tolerant mutants have been obtained, and we plan to sequence their genomes in order to identify novel mutations linked to the ethanol phenotype. We expect that we will be able to identify the specific mutations that confer ethanol resistance. The expected results should not only provide new potentially industry-relevant strains but also provide their genetic annotation, a component that is commonly missing in yeast ethanol resistance studies.