Intraspecific biodiversity and 'spoilage potential' of Brettanomyces bruxellensis in Apulian wines

The yeast Brettanomyces bruxellensis, generally considered the main oenological spoilage microbe, is able to survive during the winemaking process and it confers off-odors to wine, in reason of its ability to produce considerable amounts of volatile phenols. Forty-eight isolates of B. bruxellensis, obtained from several wines collected in Apulia (Southern Italy), were genetically characterized using an integrated approach, including a strain biodiversity analysis by Sau-PCR. Furthermore, the production of volatile phenols was assessed in wine and in synthetic medium, confirming the oenological spoilage potential of the analysed strains. Our findings indicate a remarkable genetic variability of the B. bruxellensis identified strains and corroborate the evidence of a high level of genotypic and phenotypic polymorphism within B. bruxellensis species. Moreover, the observation reported suggest that strains from wines produced in the same geographical areas often clustered differently, indicating a complex intraspecific biodiversity in the regional wine environments. Diversity in volatile phenol production reflects intraspecific biodiversity highlighted by Sau-PCR. Strains diversity linked to differences in 'spoilage potential' increase the industrial relevance of this study, allowing the design of new strategies for B. bruxellensis control in wines.