Genome Science and Technology Graduate Program, University of British Columbia, Vancouver, BC V5Z 4S6, Canada.
Department of Food Science, Wine Research Centre, Faculty of Land and Food Systems, University of British Columbia, 2205 East Mall, Vancouver, BC V6T 1Z4, Canada.
G3 (Bethesda). 2023 Aug 9;13(8). doi: 10.1093/g3journal/jkad130.
Vineyards in wine regions around the world are reservoirs of yeast with oenological potential. Saccharomyces cerevisiae ferments grape sugars to ethanol and generates flavor and aroma compounds in wine. Wineries place a high-value on identifying yeast native to their region to develop a region-specific wine program. Commercial wine strains are genetically very similar due to a population bottleneck and in-breeding compared to the diversity of S. cerevisiae from the wild and other industrial processes. We have isolated and microsatellite-typed hundreds of S. cerevisiae strains from spontaneous fermentations of grapes from the Okanagan Valley wine region in British Columbia, Canada. We chose 75 S. cerevisiae strains, based on our microsatellite clustering data, for whole genome sequencing using Illumina paired-end reads. Phylogenetic analysis shows that British Columbian S. cerevisiae strains cluster into 4 clades: Wine/European, Transpacific Oak, Beer 1/Mixed Origin, and a new clade that we have designated as Pacific West Coast Wine. The Pacific West Coast Wine clade has high nucleotide diversity and shares genomic characteristics with wild North American oak strains but also has gene flow from Wine/European and Ecuadorian clades. We analyzed gene copy number variations to find evidence of domestication and found that strains in the Wine/European and Pacific West Coast Wine clades have gene copy number variation reflective of adaptations to the wine-making environment. The "wine circle/Region B", a cluster of 5 genes acquired by horizontal gene transfer into the genome of commercial wine strains is also present in the majority of the British Columbian strains in the Wine/European clade but in a minority of the Pacific West Coast Wine clade strains. Previous studies have shown that S. cerevisiae strains isolated from Mediterranean Oak trees may be the living ancestors of European wine yeast strains. This study is the first to isolate S. cerevisiae strains with genetic similarity to nonvineyard North American Oak strains from spontaneous wine fermentations.
世界各地葡萄酒产区的葡萄园是具有酿酒潜力的酵母水库。酿酒酵母将葡萄中的糖分发酵成乙醇，并在葡萄酒中生成风味和香气化合物。酒庄非常重视识别其所在地区的本土酵母，以开发具有特定地区特色的葡萄酒项目。与野生酵母和其他工业过程中的多样性相比，商业葡萄酒菌株由于种群瓶颈和近亲繁殖，其遗传上非常相似。我们从加拿大不列颠哥伦比亚省奥肯那根谷葡萄酒产区的葡萄自然发酵中分离并微卫星分型了数百株酿酒酵母菌株。我们根据微卫星聚类数据选择了 75 株酿酒酵母菌株，基于我们的微卫星聚类数据，使用 Illumina 配对末端读取进行全基因组测序。系统发育分析表明，不列颠哥伦比亚省的酿酒酵母菌株分为 4 个分支：葡萄酒/欧洲、跨太平洋橡木、啤酒 1/混合起源，以及我们指定的新分支，即太平洋西海岸葡萄酒。太平洋西海岸葡萄酒分支具有较高的核苷酸多样性，与野生北美橡木菌株共享基因组特征，但也有来自葡萄酒/欧洲和厄瓜多尔分支的基因流。我们分析了基因拷贝数变异，以寻找驯化的证据，发现葡萄酒/欧洲和太平洋西海岸葡萄酒分支中的菌株的基因拷贝数变异反映了对酿酒环境的适应。“葡萄酒圈/区域 B”是一个由商业葡萄酒菌株通过水平基因转移获得的 5 个基因簇，也存在于葡萄酒/欧洲分支的大多数不列颠哥伦比亚菌株中，但在太平洋西海岸葡萄酒分支的少数菌株中存在。先前的研究表明，从地中海橡木树上分离的酿酒酵母菌株可能是欧洲葡萄酒酵母菌株的活祖先。本研究首次从自然葡萄酒发酵中分离出与非葡萄园北美橡木菌株具有遗传相似性的酿酒酵母菌株。
