Rapid detection and quantification of yeast species during spontaneous wine fermentation by PCR-RFLP analysis of the rDNA ITS region

PCR-RFLP analysis of the rDNA-ITS (internal transcribed spacer) region was applied to 174 yeast strains belonging to 30 species of oenological signifi cance and including 27 type strains in order to define a rapid identificati on protocol for yeast colonies. DraI-or HaeIII-PCR-RFLP patterns were speci es-specific with the exception of teleomorphic and anamorphic forms. An imp roved protocol taking about 30 h was used for the detection and quantificat ion of yeast species occurring in the course of a spontaneous wine fermenta tion at industrial level. Wine samples were taken and plated daily on an ag ar medium and the developed colonies were analysed by PCR-RFLP after 24 h o f incubation. A representative sample of these colonies was also identified by traditional methods. Both procedures gave identical results. However, P CR-RFLP analysis allowed a more precise enumeration of the yeast population s, proving to be a reliable and simple method for monitoring the developmen t of the yeast community throughout wine fermentation.