Brettanomyces bruxellensis prevalence in wines produced and marketed in Spain

The sensory deterioration of wine caused by the formation of volatile phenols (4-ethylphenol and 4-ethylguaiacol) due to the growth of the spoilage yeast Brettanomyces during the winemaking process can cause serious financial loss and problems in export trade barriers. The presence of this microorganism is increasingly common in cellars. Fast, specific and early detection of this yeast during wine production enables the oenologist and producer to take preventive measures before the phenolic aspect appears. Several methods are available for the detection of this yeast species. A new, quick and easy-to-use kit based on RT-PCR to detect Brettanomyces has appeared recently on the market. To evaluate the prevalence of this microorganism in our country and the effectiveness of this new technique, we analysed 86 red wines produced and marketed in Spain (commercialised wines or just before being bottled). We compared the results with those obtained with traditional microbial counting on selective medium and with another molecular method based on the amplification of the internal transcribed spacers (ITS1 and ITS2) of the rRNA 5.8S. Fifteen samples (17.4%) were positive for the presence of B. bruxellensis by microbiological plate counting after 5–7 days of incubation and 14 (16.3%) also gave positive results with RT-PCR analysis, after only 7 h. Of 86 wines analysed, 16 (18.6%) were positive with at least one of the methods used.