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.

负责生产乙醇的初级发酵主要由不同的菌株进行 酿酒酵母。在生产规模上，一次发酵在大罐中进行，这 包括使用自发发酵或引导发酵。在自然发酵中，必须暴露在 驻留酵母种群，而在引导发酵中，商业上可获得的酿酒酵母 添加发酵剂或活性干酵母(ADY)菌株。我们的自然发酵研究，在一种比诺上进行 加拿大不列颠哥伦比亚省奎斯门庄园(QGEW)的黑色品种表明，阿迪菌株是 发酵黑比诺的优势菌株必须，而不是本土酵母菌株。这些发现发表在《科学》杂志上。 相比之下，来自传统葡萄酒产区的葡萄酒往往以本土酵母菌株为主。我们 在引导发酵结束时还表明，接种剂，Ady菌株Lalvin®RC212 以污染的Ady菌株Lalvin®ICV-D254为主。这一数据支持最近的传统葡萄酒 地区研究发现，在引导发酵中经常存在多个酿酒酵母菌株。但是，在 在传统的葡萄酒产区，污染菌株往往是本土菌株，而在我们的研究中，它们是 由相对攻击性较强的阿迪病毒株组成。我们的结果表明，北美葡萄酒厂 独特之处在于，Ady污渍主导着自发和引导的发酵，酿酒酵母的污染物 引导发酵的菌株往往是Ady，而不是本土菌株。这项拟议的研究计划，包括 关于酵母菌在发酵葡萄酒中的菌种动态及其应激基因的表达，将有助于确定 通过将我们的知识扩展到多个北美葡萄酒厂，这种独特性是否有效。我们的Main 目标是：1)比较不同年份、不同酿酒厂和不同阶段葡萄酒中酵母菌的动态。 2)比较不同发酵阶段的酵母菌总数；3)确定 引导发酵和自发发酵中ADY酵母菌的来源；以及4)比较应激的表达 来自酵母菌的基因，它受到和不受其他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.