SACCHAROMYCES CEREVISIAE BIODIVERSITY IN MONFERRATO, NORTH WEST ITALY, AND SELECTION OF INDIGENOUS STARTER CULTURES FOR BARBERA WINE PRODUCTION

The aim of this study was to examine the biodiversity of Saccharomyces cerevisiae isolates from Barbera grapes and musts, from the Monferrato area, in the Piedmont region – North West Italy. An interdelta element PCR analysis was used to identify and discriminate 636 S. cerevisiae isolates at a strain level. Ninety-six S. cerevisiae that showed different molecular fingerprints were characterized through physiological tests and laboratory scale fermentations. A chemical analysis of experimental wines obtained from inoculated fermentations showed significant differences between the wines. The main variables considered in the strain differentiation were the residual sugars and the production of acetic acid, which ranged from 148.64 to 3.44 g/l and from 0.20 to 0.60 g/l, respectively. As a consequence, strain variability should be considered as a relevant resource to select suitable starter cultures in order to improve or characterize wines with a close bond to the geographic region.