Diversity of Saccharomyces and non-Saccharomyces yeasts in three red grape varieties cultured in the Serranía de Ronda (Spain) vine-growing region

For the first time, an ecological survey of wine yeasts present in grapes growing in two vineyards located in the region of "Serranía de Ronda" (Málaga, southern Spain) has been carried out. During the 2006 and 2007 vintages, grapes from different varieties were aseptically collected and allowed to ferment spontaneously in the laboratory. From a total of 1586 colonies isolated from microvinifications, 1281 were identified according to ITS polymorphisms and their identity confirmed by sequencing of the D1/D2 region of 26S rDNA. Most of the isolates (84%) corresponded to thirteen different non-Saccharomyces species with Kluyveromyces thermotolerans, Hanseniaspora guilliermondii, Hanseniaspora uvarum and Issatchenkia orientalis accounting for 42.7% of the total. Mitochondrial DNA restriction analysis from the Saccharomyces cerevisiae isolates revealed a low diversity since only eleven different profiles were found, nine of them corresponding to local strains and two to commercial ones that had been used in different campaigns and that very likely were disseminated from the winery to the adjacent vineyard. A different distribution of strains was found in the three grape varieties studied.