Dissemination of wine-related yeasts by migratory birds.
The present work was undertaken to evaluate the contribution of migratory birds in the environmental dissemination of yeasts. Four sites (Mazara del Vallo, Lampedusa, Ustica and Linosa), representing the main stop-over points in Sicily, were analysed during spring and autumnal bird migration and 349 birds (belonging to 10 families) were ringed and analysed for yeast presence. A total of 125 yeasts were isolated and identified by a multiple genotypic approach, consisting of restriction fragment length polymorphism (RFLP) of 5.8S rRNA gene and 26S rRNA and sequencing of D1/D2 domain of the 26S rRNA gene, which resulted in the recognition of 18 species, including the technological relevant Saccharomyces cerevisiae which were characterized at strain level applying three techniques (interdelta analysis, minisatellite analysis based on the separate amplification of three genes and microsatellite multiplex PCR of polymorphic microsatellite loci). The evaluation of the persistence of living S. cerevisiae in birds for about 12 h from ingestion of inoculated feed allowed the conclusion that yeasts with technological potential are disseminated during migration.