Microbe Secondary Domestication—The Case of CachaçaYeasts. Multiple Rounds of Artificial Selection Promote Microbe Secondary Domestication—The Case of Cachaça Yeasts

In this study we employed whole genome data to try to understand in more detail the relationships of cachaça strains among themselves and with representatives of well-established populations of S. cerevisiae, with relevance to the wine group. More specifically we wanted to know if cachaça is fermented by typical wine strains, by modified wine strains, or by strains not related to the wine group. We wanted also to assess the degree of genetic variability within the cachaça group. Also, taking advantage of the availability of complete genome data we wanted to know if domestication signatures typical of wine strains were present in cachaça yeasts or if distinct signatures could be detected. Moreover, given the recent identification of wild populations of S. cerevisiae in Brazil (Barbosa et al. 2016), their relationship with cachaça yeasts and the evaluation of possible genetic contact between these two groups were also investigated.

本研究采用全基因组数据，旨在更深入地解析卡莎萨酒（Cachaça）酵母菌株之间的亲缘关系，以及其与隶属于葡萄酒酵母类群的酿酒酵母（S. cerevisiae）经典种群代表菌株的演化关联。具体而言，本研究旨在明确卡莎萨酒的发酵过程，是由典型葡萄酒酵母菌株、改良型葡萄酒酵母菌株，还是与葡萄酒类群无关联的酵母菌株所介导。同时，本研究亦拟评估卡莎萨酒酵母类群内部的遗传变异程度。此外，依托已获取的完整基因组数据，本研究旨在探究卡莎萨酒酵母中是否存在葡萄酒酵母菌株特有的驯化特征，抑或可检测到其独有的驯化信号。更进一步，鉴于巴西境内近期发现酿酒酵母野生种群（Barbosa等，2016），本研究同时探究了该野生种群与卡莎萨酒酵母的亲缘关系，并评估了这两类菌群间潜在的遗传交流情况。