I lieviti del vino cotto abruzzese

The objective of this study was to examine the Saccharomyces and non- Saccharomyces yeast populations involved in spontaneous fermentations of vino cotto, a traditional wine produced from cooked grape must containing high levels of sugar. Only a restricted number of osmotolerant yeast species, i.e. Candida apicola, Candida zemplinina and Zygosaccharomyces bailii, were found throughout all the fermentation process, while Saccharomyces cerevisiae prevailed after 15 days of fermentation. A physiological characterization of isolates was performed in relation to the resistance to osmotic stress and ethanol concentration. The osmotolerant features of C. apicola, C. zemplinina and Z. bailii were confirmed, while S. cerevisiae strains showed three patterns of growth in responses to different glucose concentrations (2, 20, and 40%). The finding that some yeast biotypes with higher multiple stress tolerance can persist in the entire winemaking process suggests possible future candidates to be used as a starter for vino cotto production.