Yeasts associated with the spontaneously fermented grape musts obtained from cool climate white grape varieties.

The study dealt with quantitative and qualitative analysis of yeast microbiota found during spontaneous fermentation of grape musts from the white grape varieties Hibernal, Bianca and Seyval Blanc. Yeast strains were differentiated by random amplification of polymorphic DNA and pre-identified by restriction fragment length polymorphism of the 5.8S-ITS rRNA gene region. Final identification was obtained by 5.8S-ITS rRNA gene region sequencing. Metschnikowia pulcherrima, Hanseniaspora uvarum, Saccharomyces cerevisiae, Zygoascus meyerae, Wickerhamomyces anomalus and Kluyveromyces lactis strains were identified in all fermented musts. Higher yeast counts were determined in fresh musts from 2012 season compared to 2013, which directly affected their quantitative composition during the process. Musts obtained from the grapes from the Spotkaniówka vineyard were characterized by a higher microbial content compared to those obtained from the Srebrna Góra vineyard. It could be related to the microclimatic conditions in the vineyard. The grape varieties currently grown in Poland are characteristic for the cool climate region. Detailed studies on the microbiota of grapes and grape must allow for identification of yeast strains characteristic for a specific terroir and defining the 'identity' of a regional wine. [ABSTRACT FROM AUTHOR]