The purpose of this work was to investigate the presence of C. zemplinina yeasts in Sicilian musts and grapes and to identify strains of oenological interest. We report on the taxonomical reclassification of Candida yeast isolates from Sicilian musts and on the selection of one strain of oenological interest (Cz3), based on mixed micro-fermentation experiments in sterile Nero d'Avola musts. Our results show that Candida zemplinina is abundant in Sicilian grapes and musts, and that the Cz3 strain is suitable for Candida zemplinina/Saccharomyces cerevisiae mixed fermentations. The higher glycerol content and the lower ethanol level stood out as the most promising features of the wines obtained upon sequential inoculation of the Cz3 and (S. cerevisiae) NDA21 yeast starters. We therefore have isolated a Sicilian Cz strain endowed with very promising features for the future development of mixed fermentation protocols.

Aims:  The aim of this study was to identify the non‐Saccharomyces yeast populations present in the grape must microflora from wineries from different areas around the island of Sicily. Methods and Results:  Yeasts identification was conducted on 2575 colonies isolated from six musts, characterized using Wallerstein Laboratory (WL) nutrient agar, restriction analysis of the amplified 5·8S‐internal transcribed spacer region and restriction profiles of amplified 26S rDNA. In those colonies, we identified 11 different yeast species originating from wine musts from two different geographical areas of the island of Sicily. Conclusions:  We isolated non‐Saccharomyces yeasts and described the microflora in grape musts from different areas of Sicily. Moreover, we discovered two new colony morphologies for yeasts on WL agar never previously described. Significance and Impact of the Study:  This investigation is a first step in understanding the distribution of non‐Saccharomyces yeasts in grape musts from Sicily. The contribution is important as a tool for monitoring the microflora in grape musts and for establishing a new non‐Saccharomyces yeast collection; in the future, this collection will be used for understanding the significance of these yeasts in oenology.

Dr Daniela Barbera, for help with the triangle tests. We thank Dr Antonio Sparacio and the oenologist Salvatore Sparla for help with the Merlot and Nero d'Avola grapes. We also acknowledge the "Valle dell'Acate" winery for help with the Frappato grapes. Funds for this work were provided through an intramural grant of the IRVO

In recent years, the preservation of biodiversity has become an important issue. Despite much public discussion, however, current practices in the food industry seldom take account of its potential economic importance: on the contrary, the introduction of industrialized agriculture practices over large areas has often resulted in a dramatic reduction in biodiversity. In this paper, we report on the remarkable degree of biodiversity in the wine yeast populations naturally present in a small area of Sicily (Italy) where traditional (non-industrial) winery practices are still in place. Out of more than 900 Saccharomyces yeast isolates recovered from late spontaneous fermentations, we detected at least 209 strains. Most interestingly, when evaluated at the fermentation and technological level, a number of isolates were found to be superior to industrial yeast strains. Out of a selected group, isolates from two strains were used for experimental fermentations in a winery environment and the quality of the wines produced was assessed at the technological, quality and sensory levels. Given that the characteristics of the wines produced were found to be industrially appealing, the study demonstrated the economic potential of preserving the patrimony of Sicilian yeast biodiversity and highlighted the importance of maintaining traditional wine making practices.

No abstract