Comparative study of non-Saccharomycesmicroflora of musts in fermentation, by physiological and molecular methods

Non-Saccharomyces yeast isolates from musts of AC (Appellation Controlee) La Mancha in spontaneous fermentation were comparatively identified by physiological and molecular tests. The criterion of Barnett for the phenotypic identification was followed. Genetic characterization by polymerase chain reaction (PCR)/restriction fragment length polymorphism (RFLP) was made. The region between 18S and 28S rRNA genes was amplified using specific internal transcribed spacers ITS1 and ITS4 primers. The 47 non-Saccharomyces isolates produced nine different phenotypic profiles and 13 different genetic profiles, showing that PCR/RFLP can be more discriminating. The information supplied by the two methodologies was very similar. PCR/RFLP can be used to correct erroneous identifications by phenotype, and in some cases to achieve intra-species differentiation.