Comparative analysis of fermentation and enzyme expression profiles among industrial Saccharomyces cerevisiae strains

Industrial diploid strains of Saccharomyces cerevisiae are selected from natural populations and then domesticated by optimizing the preferred properties for producing products such as bread, wine, and sake. In this study, for comparing the fermentation performance of various industrial yeasts, seven diploid strains of S. cerevisiae, namely, BY4947 (laboratory yeast derived from S288C), Kyokai7 and Kyokai9 (sake yeasts), Red Star and NBRC0555 (bread yeasts), and QA23 and EC1118 (wine yeasts), were cultivated in a synthetic medium. The fermentation profiles of the seven yeast strains showed significant differences. The specific ethanol production rates of sake yeasts (Kyokai7 and Kyokai9) and wine strains (QA23 and EC1118) were higher and lower than those of laboratory strains, respectively. Targeted proteome analysis was also conducted to investigate the variation in the expression of metabolism-related enzymes. The expression profiles of central metabolism-related enzymes showed considerable variations among the industrial strains. Upregulation of the TCA cycle in wine strains was observed both in the synthetic and grape-juice media. These results suggested that these variations should be consequences of complex interactions between the domestication process, genetic polymorphism, and environmental factors such as the fermentation conditions.