OBTAINING ACTIVE DRY YEASTS BIOMASS FOR THE PRODUCTION OF PIETROASA WINES

Consumers are increasingly demanding traditional beverages such as wines that are obtained through innovative technologies and that use indigenous yeasts to preserve the concept of `terroir`. The paper presents the study performed for the exploitation the microbial diversity in the Pietroasa wine region in Romania and to obtain autochthones yeasts biomass. Yeasts were isolated from grapes and must from Feteasca regala FR) and Cabernet Sauvignon (CS) varieties cultivated at the Pietroasa Viticulture and Vinification Research and Development Station. Five yeast isolates were selected and identified by the MALDI-TOF, these belonging to the S. cerevisiae and non-Saccharomyces genera. By using these yeast isolates, active dry biomass was obtained through fermentation on a substrate based on sterilised diluted must (from the Feteasca regala and Cabernet Sauvignon varieties), synthetic sterilised media, followed by freeze-drying. Subsequently, the active dry biomass was used to obtain wines, using two types of nutrients: ET (Energyvin Thiols) and NO (Nutristart® ORG). All studied yeast isolates showed a promising potential for obtaining white wine from Feteasca regala grapes and rosé wine from the Cabernet Sauvignon grapes variety.