Department of Biotechnology, University of Verona, 37134 Verona, Italy.
Bioenologia 2.0, 31046 Oderzo, Italy.
Food Res Int. 2019 Aug;122:432-442. doi: 10.1016/j.foodres.2019.04.043. Epub 2019 Apr 19.
The inoculation of Saccharomyces cerevisiae starter cultures in grape musts is a common practice in wineries worldwide; however, native non-Saccharomyces yeast species are increasingly investigated as co-starters to augment the complexity and regionality of wine. In this study, an extensive collection of non-Saccharomyces yeasts from high-sugar matrices was created and screened with the aim to discover new strains with potentially positive oenological traits. After mining >400 yeasts from 167 samples collected across multiple Italian regions, the isolates were identified based on RAPD-PCR analysis and ITS sequencing. About one quarter of them, belonging to the genera Starmerella, Lachancea and Metschnikowia, were picked up for an in-depth molecular and physiological characterization, since these yeasts were well strewed and have a good oenological reputation. Following the genotyping, stress tolerance assays, enzymatic activity trials and single inoculum fermentations, a huge diversity was acknowledged within and between the species. Strains of S. bacillaris showed a high tolerance to ethanol and increased glycerol production, L. thermotolerans reduced volatile acidity while increasing total acidity with lactic acid, and Metschnikowia spp. exhibited remarkable aroma-related enzymatic activities, which are all prized features in winemaking. Since most of the characteristics analyzed were species and strain dependent, the obtained results are valuable for the selection of a new generation of co-starters for attempting mixed fermentation strategies aimed to improve the overall quality of regional wine.
向葡萄汁中接种酿酒酵母（Saccharomyces cerevisiae）是世界各地酿酒厂的常见做法；然而，越来越多的研究人员开始关注本土非酿酒酵母（non-Saccharomyces yeast），将其作为共发酵剂，以增加葡萄酒的复杂性和地域特色。在本研究中，从高糖基质中创建并筛选了大量非酿酒酵母，旨在发现具有潜在积极酿造特性的新菌株。从意大利 167 个地区采集的 167 个样本中挖掘出>400 株酵母后，基于随机扩增多态性 DNA（RAPD）-PCR 分析和 ITS 测序对分离株进行了鉴定。由于这些酵母分布广泛且具有良好的酿造声誉，约四分之一属于 Stamerella、Lachancea 和 Metschnikowia 属的酵母被挑选出来进行深入的分子和生理特性分析。在进行基因分型、应激耐受试验、酶活性试验和单接种发酵后，确认了种内和种间的多样性。Saccharomyces bacillaris 菌株对乙醇具有较高的耐受性，并且能够增加甘油产量；Lachancea thermotolerans 降低了挥发性酸度，同时增加了乳酸产生的总酸度；Metschnikowia spp. 表现出显著的与香气相关的酶活性，这些都是酿造过程中的宝贵特性。由于分析的大多数特性都取决于菌株，因此获得的结果对于选择新一代共发酵剂用于尝试混合发酵策略以提高地区葡萄酒的整体质量具有重要价值。
