Wine microbiology researchers studies local microflora in order to selection of yeast strains,providing through controlled fermentation, high quality wines. It put thus, the theoretical basis of drivenfermentation from biological point of view. Knowing the main species of yeasts of the vineyard, theirmorphological, physiological and oenological characteristics, the relationship between them can easilyoccur in the alcoholic fermentation of must and can be easily prevented many " wine accidents." Thepresent study from the viti-vinicol Cernavoda Centre, from Murfatlar vineyard conducted in 2009-2011period, has the aims:- isolation and identification of wine yeast species existing in spontaneousmicroflora;- morpho-physiological and biochemical,charac-terization and their taxonomic classification.This study will determine the succession of yeasts species during alcoholic fermentation and the proportionthey have in different stages of vinification. The pure cultures obtained and analyzed will represented adata base for the future researches. Finally, were isolated 183 yeasts strains from the grapes, unfermentedmusts and musts in different stages of fermentation. The methods of sampling, isolation, culture andclasification used in researches, were the classics and described by Domerq (1956), Lindner (1913),Lodder (1970), Kreger van Rij (1984) and Kurtzman and Fell (2006). According to the internationalclassification these 183 yeasts strains belong to two classes: Ascomycetes with three genres(Saccharomyces, Hansenula, Pichia) and Deuteromycetes with four genres (Candida, Kloeckera,Rhodotorula and Torulopsis). During alcoholic fermentation, the microorganisms present in musts,develops in a certain succession, which is conditional by the relationships that are established betweendifferent groups and were identified species that start fermentation, fermentation leading species andspecies present only at the end of alcoholic fermentation, called “species for wine finishing”. Succession ofyeasts species is influenced by increasing temperature and alcoholic degree and the degree and intensity ofsulfur administration.

yeasts species, alcoholic fermentation, yeasts isolation

Presentation: oral