Identification and characterization of indigenous B.C. wine yeast strains

BC省土著的鉴定和特征

• 批准号: RGPIN-2016-04261
• 负责人: Measday, Vivien
• 金额: $ 2.04万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=659458
• 关键词: Identification; characterization; indigenous; B.C.; wine

In competitive wine markets, British Columbian (BC) wineries must create high-value wines that express the unique character, or terroir, of their region. Wines are produced by inoculated fermentation with commercial strains of the wine yeast Saccharomyces cerevisiae (S. cerevisiae) or by spontaneous fermentation, which relies on yeast residing on grapes and winery equipment. Spontaneous fermentations are risky but can produce organoleptically complex wines if indigenous yeast species dominate the fermentation. The goal of my research is to identify indigenous yeast present in BC vineyards with enological potential that showcase BC terroir. Since 2013, we have collaborated with two BC wineries that perform Pinot Gris and Pinot Noir spontaneous fermentations. Concurrent with winery fermentations, we harvested the same grape varietals and fermented them in the lab. We isolated S. cerevisiae strains from winery and vineyard fermentations, performed microsatellite profiling and compared the data to a microsatellite database that we compiled of over 120 commercial S. cerevisiae wine yeast strains. We have identified a unique indigenous subpopulation of S. cerevisiae and unexpectedly identified strains of S. bayanus in the fermentations. Both our novel S. cerevisiae and S. bayanus strains have enological potential.***Objective 1. Phenotypic and Metabolic profiling of S. cerevisiae strains isolated from spontaneous fermentations. Bayesian clustering analysis of our S. cerevisiae strains revealed 12 population clusters. We will perform small-scale fermentations with representative strains from each cluster. Strains with vigorous fermentation profiles will be analyzed for positive flavor compounds. Phenotypic analysis of traits important for wine production and whole genome sequencing of strains with enological potential will be performed.***Objective 2. Identification of yeast/fungal species during spontaneous fermentation. Nonconventional yeasts such as Metschnikowia are found in spontaneous fermentations and contribute sensorial complexity to the wine. We will identify non-Saccharomyces species present in our winery and vineyard fermentations by direct DNA extraction from wine samples and Illumina next generation sequencing. Our goal is to analyze the contribution of nonconventional yeast to the winery and vineyard fermentations. ***Objective 3. Genetic characterization of BC S. bayanus isolates and evaluation of S. bayanus and non-Saccharomyces yeast fermentation potential. We isolated unique strains of S. bayanus from Pinot Gris spontaneous fermentations. We will generate an S. bayanus reference database using commercial and published strains to classify subpopulations. S. bayanus and non-Saccharomyces strains will be co-inoculated with S. cerevisiae strains to identify ideal strain combinations for high quality wine production. **

在竞争激烈的葡萄酒市场，不列颠哥伦比亚省（BC）的酒庄必须创造出高价值的葡萄酒，表达独特的性格，或风土，他们的地区。葡萄酒是用酿酒酵母的商业菌株接种发酵或自发发酵生产的，这依赖于驻留在葡萄和酿酒厂设备上的酵母。自发发酵是有风险的，但如果本地酵母菌种主导发酵，则可以生产出具有复杂感官的葡萄酒。我的研究目标是确定本地酵母存在于不列颠哥伦比亚省葡萄园与酿酒潜力，展示不列颠哥伦比亚省风土。自2013年以来，我们与卑诗省的两家酒庄合作，进行灰比诺和黑皮诺的自发发酵。在酿酒厂发酵的同时，我们收获了相同的葡萄品种，并在实验室中发酵。我们从酿酒厂和葡萄园发酵中分离出酿酒葡萄球菌菌株，进行微卫星分析，并将数据与我们编制的超过120个商业酿酒葡萄球菌葡萄酒酵母菌的微卫星数据库进行比较。我们已经鉴定出了酿酒酵母的一个独特的本土亚群，并且意外地在发酵过程中鉴定出了bayanus菌株。我们的新酿酒葡萄球菌和bayanus葡萄球菌都具有酿酒潜力。* * *目标1。酿酒酵母自然发酵分离菌株的表型和代谢谱分析。贝叶斯聚类分析显示酿酒葡萄球菌有12个群体聚类。我们将用每个集群的代表性菌株进行小规模发酵。具有强烈发酵特征的菌株将被分析为阳性风味化合物。对葡萄酒生产有重要意义的性状进行表型分析，并对具有酿酒潜力的菌株进行全基因组测序。* * *目标2。自然发酵过程中酵母菌/真菌种类的鉴定。非传统的酵母，如Metschnikowia，是在自发发酵中发现的，为葡萄酒的感官复杂性做出了贡献。我们将通过直接从葡萄酒样品中提取DNA和Illumina下一代测序来鉴定我们酒厂和葡萄园发酵中存在的非酵母菌种。我们的目标是分析非常规酵母对酿酒厂和葡萄园发酵的贡献。* * *目标3。巴芽孢杆菌分离株的遗传特性及巴芽孢杆菌和非酵母菌发酵潜力评价。从灰皮诺自然发酵中分离到独特的bayanus菌株。我们将利用商业和已发表的菌株建立一个bayanus参考数据库来分类亚群。将bayanus和非saccharomyces菌株与酿酒酵母菌株共接种，以确定高品质葡萄酒生产的理想菌株组合。**