Padilla Beatriz, García-Fernández David, González Beatriz, Izidoro Iara, Esteve-Zarzoso Braulio, Beltran Gemma, Mas Albert
Departament de Bioquímica i Biotecnologia, Facultat d' Enologia, Universitat Rovira i Virgili Tarragona, Spain.
Front Microbiol. 2016 Jun 15;7:930. doi: 10.3389/fmicb.2016.00930. eCollection 2016.
Climate, soil, and grape varieties are the primary characteristics of terroir and lead to the definition of various appellations of origin. However, the microbiota associated with grapes are also affected by these conditions and can leave a footprint in a wine that will be part of the characteristics of terroir. Thus, a description of the yeast microbiota within a vineyard is of interest not only to provide a better understanding of the winemaking process, but also to understand the source of microorganisms that maintain a microbial footprint in wine from the examined vineyard. In this study, two typical grape varieties, Grenache and Carignan, have been sampled from four different vineyards in the DOQ Priorat winegrowing region. Afterward, eight spontaneous alcoholic fermentations containing only grapes from one sampling point and of one variety were conducted at laboratory scale. The fermentation kinetics and yeast population dynamics within each fermentation experiment were evaluated. Yeast identification was performed by RFLP-PCR of the 5.8S-ITS region and by sequencing D1/D2 of the 26S rRNA gene of the isolates. The fermentation kinetics did not indicate clear differences between the two varieties of grapes or among vineyards. Approximately 1,400 isolates were identified, exhibiting high species richness in some fermentations. Of all the isolates studied, approximately 60% belong to the genus Hanseniaspora, 16% to Saccharomyces, and 11% to Candida. Other minor genera, such as Hansenula, Issatchenkia, Kluyveromyces, Saccharomycodes, and Zygosaccharomyces, were also found. The distribution of the identified yeast throughout the fermentation process was studied, and Saccharomyces cerevisiae was found to be present mainly at the end of the fermentation process, while Aureobasidium pullulans was isolated primarily during the first days of fermentation in three of the eight spontaneous fermentations. This work highlights the complexity and diversity of the vineyard ecosystem, which contains yeasts from different species. The description of this yeast diversity will lead to the selection of native microbiota that can be used to produce quality wines with the characteristics of the Priorat.
气候、土壤和葡萄品种是风土的主要特征，决定了各种原产地命名。然而，与葡萄相关的微生物群也受这些条件的影响，并能在葡萄酒中留下印记，成为风土特征的一部分。因此，描述葡萄园中的酵母微生物群不仅有助于更好地理解酿酒过程，还能了解在来自所研究葡萄园的葡萄酒中留下微生物印记的微生物来源。在本研究中，从DOQ普里奥拉托葡萄酒产区的四个不同葡萄园采集了两种典型葡萄品种，歌海娜和佳丽酿。随后，在实验室规模下进行了八次仅含来自一个采样点的一个品种葡萄的自发酒精发酵。评估了每个发酵实验中的发酵动力学和酵母种群动态。通过对5.8S-ITS区域进行RFLP-PCR以及对分离株的26S rRNA基因的D1/D2区域进行测序来进行酵母鉴定。发酵动力学并未表明这两个葡萄品种或不同葡萄园之间存在明显差异。共鉴定出约1400个分离株，在一些发酵过程中显示出较高的物种丰富度。在所研究的所有分离株中，约60%属于汉逊酵母属，16%属于酿酒酵母属，11%属于念珠菌属。还发现了其他一些次要属，如汉逊酵母属、伊萨酵母属、克鲁维酵母属、类酵母属和接合酵母属。研究了已鉴定酵母在整个发酵过程中的分布，发现酿酒酵母主要在发酵过程结束时出现，而在八次自发发酵中的三次中，短梗霉主要在发酵的最初几天被分离出来。这项工作突出了葡萄园生态系统的复杂性和多样性，其中包含来自不同物种的酵母。对这种酵母多样性的描述将有助于选择本地微生物群，用于生产具有普里奥拉托特色的优质葡萄酒。
