Unidade de Bioenergia, LNEG, Estrada do Paço do Lumiar, 22, 1649-038, Lisbon, Portugal.
J Ind Microbiol Biotechnol. 2011 Jan;38(1):127-32. doi: 10.1007/s10295-010-0837-z. Epub 2010 Sep 3.
The industrial use of starter cultures containing a consortium of different strains from the same species is nowadays seen as a possible strategy to enhance the organoleptic complexity of wines. To assess the relative contribution of each strain to the final product it is essential to quantify population evolution during the wine fermentation process, which requires strain-specific methods to identify and differentiate each strain. In the present study, a molecular method based on analysis of the polymorphisms exhibited by the PCR-amplification of the delta regions of three Saccharomyces cerevisiae strains was developed. A set of three pairs of primers (delta1-delta2, delta12-delta2, delta12-delta21) was used for each strain, and analysis of the resulting polymorphism patterns showed that the delta12-delta2 primer pair exhibited the highest resolution and discriminatory power. Thus, this pair of primers was selected to monitor the population evolution of a laboratory-scale wine fermentation performed in synthetic grape juice that was inoculated with similar amounts of each strain. The results showed that all strains grew together during the exponential growth phase (2-3 days) and maintained high cell density values (10(6)-10(7) cfu ml(-1)) throughout the stationary growth phase without significantly changing their relative population proportion, thus indicating that each strain can influence the chemical composition and final flavor of wine, albeit at different levels. This study also showed that PCR-amplification of DNA delta sequences of S. cerevisiae strains is a reproducible, strain-specific and simple method that can be used successfully to monitor yeast strain population dynamics during wine fermentations.
如今，在工业中使用含有同一物种不同菌株的混合发酵剂被视为提高葡萄酒感官复杂性的一种可行策略。为了评估每个菌株对最终产品的相对贡献，必须在葡萄酒发酵过程中定量分析种群演变，这就需要采用菌株特异性方法来识别和区分每个菌株。本研究开发了一种基于 PCR 扩增三种酿酒酵母菌株 delta 区多态性分析的分子方法。为每种菌株设计了一套三对引物（delta1-delta2、delta12-delta2、delta12-delta21），对所得多态性模式的分析表明，delta12-delta2 引物对具有最高的分辨率和区分能力。因此，选择这对引物来监测在类似数量的每种菌株接种的合成葡萄汁中进行的实验室规模葡萄酒发酵的种群演变。结果表明，所有菌株在指数生长阶段（2-3 天）共同生长，并在静止生长阶段保持高细胞密度值（10(6)-10(7) cfu ml(-1))，而相对种群比例没有显著变化，这表明每个菌株都可以影响葡萄酒的化学成分和最终风味，尽管影响程度不同。本研究还表明，酿酒酵母菌株 DNA delta 序列的 PCR 扩增是一种可重复、菌株特异性和简单的方法，可成功用于监测葡萄酒发酵过程中酵母菌株种群动态。
