The most important oenological characteristics of high-quality sparkling wines are high content of acidity and low pH. Racemes are late-maturing grapes of Grillo variety characterized by low pH and high content of tartaric and malic acids and, due to their intrinsic characteristics, might represent an interesting technological solution to increase acid quality of base sparkling wine. To this purpose, the use of yeasts able to ferment grape must at very low pH is mandatory for the success of the process. In this work, 261 Saccharomyces cerevisiae isolated from spontaneous vinifications of Grillo grape racemes were subject to intraspecific characterization by interdelta analysis which evidenced a total population consisting of 82 strains which were screened for their basis of technological traits including SO₂ and alcohol tolerance, flocculence, growth at low temperatures and qualitative features such as H₂S production. Eleven strains with interesting technological performance in vitro were inoculated into musts obtained from racemes of Grillo grape variety and microfermentation were monitored. For the first time an ecological investigation of yeast associated to raceme grapes has been carried out and provided an innovative strategy to improve the acidity of a Sicilian sparkling base wine from Grillo grape variety.

中文翻译：

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与Grillo葡萄品种的外消旋体相关的酿酒酵母菌株的多样性。

高品质起泡酒最重要的酿酒学特征是酸度高，pH低。外消旋体是Grillo品种的晚熟葡萄，其特征在于pH值低，酒石酸和苹果酸含量高，由于其固有特性，可能代表一种提高基础起泡酒酸度的有趣技术解决方案。为此，必须使用能够在非常低的pH值下发酵葡萄的酵母，才能成功实现该过程。在这项工作中，对通过自发提纯的格里洛葡萄消旋体分离出的261个酿酒酵母进行了种间特征分析（通过间质分析），这证明总人口包括82个菌株，这些菌株根据其技术特性（包括SO）进行了筛选。₂耐酒精性，絮凝性，低温下的生长以及H ₂ S生产等定性特征。从Grillo葡萄品种的外消旋体中获得了11株在体外具有有趣技术性能的菌株，并对其进行了监测。首次进行了与总状花序葡萄相关的酵母的生态学研究，并提供了创新的策略来提高Grillo葡萄品种的西西里起泡基酒的酸度。