Improvement of autochthonous Saccharomyces cerevisiae by rapid laboratory evolution technique of genome shuffling.

Abstract

The process of selecting indigenous Saccharomyces cerevisiae strains as a starter culture for specific fermentation has several requisites, including the assessment of distinct parameters based on desirable and traditional enological criteria. In most wineries, commercial S. cerevisiae strains are used for wine fermentation. However, it is rare to find indigenous S. cerevisiae strains used in wine production, even though these isolates are better adapted to specific regions and are often preferred for producing local fruit wines. Here, the identification and characterization of indigenous S. cerevisiae were carried out by 28S rRNA sequencing, followed by Fourier transform infrared spectroscopy analysis for further confirmation. The strain improvement technique of genome shuffling was incorporated to ameliorate sugar tolerance and enhance alcohol production in the S. cerevisiae RHTD10 strain. As a result, it was observed that the improved strain from the third round of shuffling tolerated sugar stress of 30% and produced 10.14 ± 0.21% of alcohol, which is higher than the wild strain of 7.11 ± 0.22% alcohol.