Multi-omics study revealed the genetic basis of beer flavor quality in yeast

Beer is produced by fermenting cereals with yeast that primarily include ale beer fermented by Saccharomyces cerevisiae or lager beer by S. pastorianus. The strain of Saccharomyces is the critical genetic that determines the flavor of beer. Multi-omics of the genome, transcriptome and metabolome of 53 strains of Saccharomyces and an association analysis were performed in this study. A total of 293 flavor substances were identified and 123,426 SNPs from all the strains were selected for GWAS. A total of 441 significant SNPs were associated with 400 genes that are related to 18 flavor substances, and 118 core genes were obtained by WGCNA that used 1147 and 2392 shared differentially expressed genes throughout the whole fermentation process in five ale and four lager strains, respectively. Furthermore, EHT1, BAT1, LEU1 and IRA1 were selected to verify their gene function, and the corresponding flavor substances in beer were significantly altered. Notably, IRA1 is a novel gene related to the synthesis of acids. This study not only helps to understand the synthesis and regulatory mechanism of flavor substances in beer but also provides important genetic clues for their genetic improvement and the creation of novel Saccharomyces varieties to produce new types of beer.