RESEARCHS REGARDING TAXONOMIC IDENTIFICATION OF SPONTANEOUS MICROFLORA FROM VITI-VINICOL CERNAVODA CENTRE FROM MURFATLAR VINEYARD

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 driven fermentation from biological point of view. Knowing the main species of yeasts of the vineyard, their morphological, physiological and oenological characteristics, the relationship between them can easily occur in the alcoholic fermentation of must and can be easily prevented many " wine accidents." The present study from the viti-vinicol Cernavoda Centre, from Murfatlar vineyard conducted in 2009-2011 period, has the aims:- isolation and identification of wine yeast species existing in spontaneous microflora;- morpho-physiological and biochemical,charac-terization and their taxonomic classification. This study will determine the succession of yeasts species during alcoholic fermentation and the proportion they have in different stages of vinification. The pure cultures obtained and analyzed will represented a data base for the future researches. Finally, were isolated 183 yeasts strains from the grapes, unfermented musts and musts in different stages of fermentation. The methods of sampling, isolation, culture and clasification 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 international classification 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 between different groups and were identified species that start fermentation, fermentation leading species and species present only at the end of alcoholic fermentation, called "species for wine finishing". Succession of yeasts species is influenced by increasing temperature and alcoholic degree and the degree and intensity of sulfur administration.