QTL mapping of volatile compound production in Saccharomyces cerevisiae during alcoholic fermentation - genotypic data

Secondary metabolites produced by the yeast Saccharomyces cerevisiae during wine fermentation, mainly esters, higher alcohols and organic acids, play a vital role for the quality and perception of finished wine. Their production is driven by the metabolic properties of the yeast and therefore strain dependent.To identify the genomic and metabolic bases for the formation of these molecules we performed a quantitative trait locus (QTL)-mapping with 130 F2 segregants from a crossing of two S. cerevisiae strains used for the production of wine. The segregants were individually genotyped by next-generation sequencing and phenotyped by measuring extracellular metabolites, using high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS).Using linkage analysis we identified 46 QTLs in the genome that influence the formation of 28 volatile secondary metabolites. In addition 13 QTLs were found influencing fermentation parameters, substrate consumption and main metabolite production. For some traits several, partly interacting, regions were detected. By performing reciprocal hemizygosity analysis (RHA) we could identify 12 responsible allelic variants within 9 of the detected QTLs. The found variants have an influence on the production of characteristic sensorial compounds, like amyl acetate, isoamyl alcohol and isoamyl actetate, as well as industrial relevant chemicals, like higher alcohols and fatty acids.The identification of allelic variation impacting wine aroma opens the way for tailoring S. cerevisiae strains for commercial applications.