Biodiversity of yeasts isolated during spontaneous fermentation of cool climate grape musts

Abstract

Biodiversity of native yeasts, especially in winemaking, has hidden potential. In order to use the value of non-Saccharomyces strains in wine production and to minimise the possibility of its deterioration, it is necessary to thoroughly study the yeast cultures present on grape fruits and in grape must, as well as their metabolic properties. The aim of the study was to characterise the yeast microbiota found during spontaneous fermentation of grape musts obtained from grape varieties 'Rondo', 'Regent' and 'Johanniter'. Grapes from two vineyards (Srebrna Góra and Zadora) located in southern Poland were used for the research. Succession of subsequent groups of yeasts was observed during the process. Metschnikowia pulcherrima yeasts were identified both at the beginning and the end of the process. Hanseniaspora uvarum, Wickerhamomyces onychis and Torulaspora delbrueckii strains were also identified during the fermentation. Torulaspora delbrueckii and Wickerhamomyces onychis strains were identified only in grape musts obtained from grapes of the Zadora vineyard. These strains may be characteristic of this vineyard and shape the identity of wines formed in it. Our research has provided specific knowledge on the biodiversity of yeast cultures on grapes and during their spontaneous fermentation. The research results presented indicate the possibility of using native strains for fermentation of grape musts, allowing to obtain a product with favourable chemical composition and sensory profile.

The Content of Selected Bioactive Compounds in Wines Produced from Dehydrated Grapes of the Hybrid Variety ‘Hibernal’ as a Factor Determining the Method of Producing Straw Wines

“…Wines A and B were rated as wines with an intense amber colour ( Figure 2 ), full flavor, and a long finish. Both in terms of aroma and taste, flavors defined as typical for passito wines prevailed (i.e., mainly dried fruit, honey, caramel and nuts [ 3 , 5 , 6 ]). The high alcohol content of these wines (18%) was fully palpable and also visible through “tears” on the walls of the glass [ 55 ].…”

“…In general, the nose and palate is met with a complex, alluring blend of peaches, dried apricots, and marmalade, with flavours of almonds and honey. The intense mouthfeel is balanced by a clean, fresh, and very long finish of dried apricots [ 3 , 4 , 5 ].…”

“…Generally, it is only possible to harvest grapes with a relatively low extract (usually 17–23° Brix), although these can give good, fragrant dry, or semi-dry wines with a balancing acidity. [ 5 ]. The only way to obtain dessert wines is to use special production methods.…”

The Use of Yeast Mixed Cultures for Deacidification and Improvement of the Composition of Cold Climate Grape Wines

“…Strains of Saccharomyces cerevisiae MH020215, Zygosaccharomyces bailii 749 and Metschnikowia pulcherrima MG970690 from the collection of Department of Fermentation Technology and Microbiology, Faculty of Food Technology, University of Agriculture in Krakow (Poland) were used in this research. Metschnikowia pulcherrima MG970690 and Saccharomyces cerevisiae MH020215 strains used for the research were isolated from spontaneous grape fermentation [ 71 , 72 , 73 ].…”

Physicochemical characterization of wines produced using indigenous yeasts from cold climate grapes

“…The isolation and identification of yeast strains was carried out by the Authors at the Department of Fermentation Technology and Microbiology (University of Agriculture in Krakow). Methods for isolation and identifying microorganisms are described in detail in previous publications [18][19][20]. The identification of yeasts was based on the morphological characteristics of the colonies, biochemical tests and molecular techniques (DNA extraction and RAPD-PCR analysis, amplification of the 5.8S-ITS rRNA gene region, PCR-RFLP analysis, 5.8S-ITSrRNA gene region sequencing).…”