Studying on genetic diversity and metabolic differences of Saccharomyces cerevisiae in Baijiu

Baijiu (a Chinese liquor), one of the six world-renowned distilled liquors, is popular among consumers, and Saccharomyces cerevisiae plays the most important role. However, the diversity and metabolic differences of S. cerevisiae Baijiu yeasts remain unclear. Here, we first studied S. cerevisiae strains isolated from fermentative agents and then analyzed the environmental tolerance and metabolomic differences among different S. cerevisiae strains. The 29 S. cerevisiae strains were classified into 14 genotypes based on DNA fingerprints. Environmental tolerance analysis revealed differences among yeasts. A total of 88 classes of 854 secondary metabolites were detected via liquid chromatography coupled with tandem mass spectrometry (LC‒MS/MS), 15 of which accounted for more than 1%, and carboxylic acids and their derivatives accounted for the highest percentage (20.73%), followed by benzene and substituted derivatives (12.76%). Both OPLS-DA and differentially abundant metabolite analysis revealed that the metabolites of the 14 S. cerevisiae genotypes were significantly different, and the differentially abundant metabolites l-erythrulose, 5(s)-HpETE, kaempferide, and cellobiose were obtained. Metabolic pathway analysis revealed that the metabolism of glycine, serine, and threonine differed significantly (p < 0.05). These results revealed the phenotypic diversity of industrial Baijiu yeasts and provided additional options for the utilization of S. cerevisiae yeasts in the brewing industry.