Data from: QTL mapping of volatile compound production in Saccharomyces cerevisiae during alcoholic fermentation

Background: The volatile metabolites produced by Saccharomyces cerevisiae during alcoholic fermentation, which are mainly esters, higher alcohols and organic acids, play a vital role in the quality and perception of fermented beverages, such as wine. Although the metabolic pathways and genes behind yeast fermentative aroma formation are well described, little is known about the genetic mechanisms underlying variations between strains in the production of these aroma compounds. To increase our knowledge about the links between genetic variation and volatile production, we performed quantitative trait locus (QTL) mapping using 130 F2-meiotic segregants from two S. cerevisiae wine strains. The segregants were individually genotyped by next-generation sequencing and separately phenotyped during wine fermentation. Results: Using different QTL mapping strategies, we were able to identify 65 QTLs in the genome, including 55 that influence the formation of 30 volatile secondary metabolites, 14 with an effect on sugar consumption and central carbon metabolite production, and 7 influencing fermentation parameters. For ethyl lactate, ethyl octanoate and propanol formation, we discovered 2 interacting QTLs each. Within 9 of the detected regions, we validated the contribution of 13 genes in the observed phenotypic variation by reciprocal hemizygosity analysis. These genes are involved in nitrogen uptake and metabolism (AGP1, ALP1, ILV6, LEU9), central carbon metabolism (HXT3, MAE1), fatty acid synthesis (FAS1) and regulation (AGP2, IXR1, NRG1, RGS2, RGT1, SIR2) and explain variations in the production of characteristic sensorial esters (e.g., 2-phenylethyl acetate, 2-metyhlpropyl acetate and ethyl hexanoate), higher alcohols and fatty acids. Conclusions: The detection of QTLs and their 51 interactions emphasizes the complexity of yeast fermentative aroma formation. The validation of underlying allelic variants increases knowledge about genetic variation impacting metabolic pathways that lead to the synthesis of sensorial important compounds. As a result, this work lays the foundation for tailoring S. cerevisiae strains with optimized volatile metabolite production for fermented beverages and other biotechnological applications.背景：酿酒酵母(Saccharomyces cerevisiae)在酒精发酵过程中产生的挥发性代谢产物（主要为酯类、高级醇与有机酸），对葡萄酒等发酵饮料的品质与感官体验至关重要。尽管酵母发酵香气形成背后的代谢通路与相关基因已得到充分阐释，但不同菌株间此类香气化合物产量差异的遗传机制仍知之甚少。为加深我们对遗传变异与挥发性产物生成之间关联的认知，本研究以两株酿酒酵母葡萄酒菌株的130个F2减数分裂分离株(F2-meiotic segregants)为材料，开展了数量性状位点(QTL, quantitative trait locus)定位分析。所有分离株均通过下一代测序(next-generation sequencing)完成单独基因型分型，并在葡萄酒发酵过程中分别进行表型鉴定。 结果：通过多种QTL定位策略，我们在基因组中鉴定出65个QTL，其中55个与30种挥发性次级代谢产物的形成相关，14个影响糖分消耗与中心碳代谢产物的生成，另有7个调控发酵参数。针对乳酸乙酯、辛酸乙酯与丙醇的合成，我们分别发现了2个互作QTL。在其中9个检测到的基因组区域内，我们通过双向半合子分析(reciprocal hemizygosity analysis)验证了13个基因对观测到的表型变异的贡献。这些基因涉及氮摄取与代谢（AGP1、ALP1、ILV6、LEU9）、中心碳代谢（HXT3、MAE1）、脂肪酸合成（FAS1）以及基因调控通路（AGP2、IXR1、NRG1、RGS2、RGT1、SIR2），可解释特征性感官酯类（如2-苯乙基乙酸酯、2-甲基丙基乙酸酯与己酸乙酯）、高级醇及脂肪酸的产量变异。 结论：QTL的鉴定及其51个互作关系凸显了酵母发酵香气形成过程的复杂性。对潜在等位变异的验证，增进了我们对影响感官重要化合物合成的代谢通路相关遗传变异的认知。本研究为定制化改造酿酒酵母菌株，使其在发酵饮料及其他生物技术应用中实现挥发性代谢产物的最优产量奠定了基础。