Population dynamics of wine yeast during spontaneous and guided fermentations and the expression of stress genes as affected by interactions between different strains of yeasts.

初级发酵负责乙醇的生产，主要由不同的菌株进行。 酿酒酵母在操作规模上，初级发酵在大罐中进行， 包括使用自发或引导发酵。在自发发酵中，果汁暴露在 而在引导发酵中，商业上可获得的S.酿酒酵母 添加发酵剂或活性干酵母（ADY）菌株。我们的自然发酵研究，进行了一个比诺 加拿大不列颠哥伦比亚省的Quails' Gate Estate Winery（QGEW）的黑葡萄品种表明，ADY菌株 黑比诺发酵的优势菌株必须，而不是土著酵母菌株。这些发现 这与传统葡萄酒产区的葡萄酒形成了鲜明对比，在传统葡萄酒产区，土著酵母菌株往往占主导地位。我们 还表明，在指导发酵结束时，接种物ADY菌株Lalvin® RC 212与对照菌株Lalvin® RC 212具有相同的生物活性。 污染物ADY菌株Lalvin® ICV-D254占优势。这一数据支持了近期传统葡萄酒 区域发现，多株S.酿酒酵母通常存在于导向发酵中。但在 在传统的葡萄酒产区，污染菌株往往是土著菌株，而在我们的研究中， 由相对具有攻击性的ADY菌株组成。我们的研究结果表明，北美的葡萄酒厂是 独特之处在于ADY染色主导自发和引导发酵，并且S.酿酒酵母污染物 引导发酵的菌株倾向于ADY，而不是本土菌株。这项研究计划，与 关于酵母菌株动力学及其在发酵葡萄酒中的应激基因表达，将有助于确定 通过将我们的知识扩展到多个北美酒庄，这种独特性是否有效。我们的主要 目的是：1）比较不同年份、不同酒厂和不同阶段的葡萄酒酵母菌株动态。 发酵; 2）比较发酵的不同阶段之间的总酵母菌群; 3）确定发酵的不同阶段之间的总酵母菌群; 4）确定发酵的不同阶段之间的总酵母菌群。 ADY酵母菌株的来源; 4）比较了诱导发酵和自发发酵中ADY酵母菌株的应激表达 来自酵母的基因，其经受和不经受来自其它ADY菌株的竞争。

Primary fermentation, which is responsible for ethanol production, is mainly conducted by different strains of Saccharomyces cerevisiae. At an operational scale, primary fermentation is conducted in large tanks, which involves using either spontaneous or guided fermentation. In spontaneous fermentation, the must is exposed to the resident yeast population, whereas in guided fermentation, a commercially available S. cerevisiae yeast starter or active dry yeast (ADY) strain is added. Our spontaneous fermentation studies, conducted on a Pinot Noir variety at Quails' Gate Estate Winery (QGEW) in British Columbia, Canada show that ADY strains are the dominant strains fermenting Pinot Noir must, as opposed to indigenous yeast strains. These findings are in contrast to those from traditional wine-producing regions where indigenous yeast strains tend to dominate. We also showed, at the end of guided fermentation, that the inoculant, ADY strain Lalvin® RC212, was equally dominant with a contaminant ADY strain Lalvin® ICV-D254. This data supports recent traditional wine region findings that multiple strains of S. cerevisiae are often present in guided fermentations. However, in traditional wine regions, contaminant strains tend to be indigenous strains, whereas in our studies, they are comprised of relatively aggressive ADY strains. Our results point to the idea that North American wineries are unique, in that ADY stains dominate spontaneous and guided fermentations and that S. cerevisiae contaminants of guided fermentation tend to be ADY and not indigenous stains. This proposed research program, with respect to yeast strain dynamics and their expression of stress genes in fermenting wine, will help to determine whether this uniqueness is valid by expanding our knowledge to multiple North American wineries. Our main objectives are to: 1) compare yeast strain dynamics of wine between different years, wineries, and stages of fermentation; 2) compare the total yeast community between different stages of fermentation; 3) determine the source of ADY yeast stains in guided and spontaneous fermentations; and 4) compare the expression of stress genes from yeasts, which are subjected to and not subjected to competition from other ADY strains.