Taqman real-time PCR for the detection and enumeration of Saccharomyces cerevisiae in wine

Saccharomyces cerevisiae is the main yeast species responsible for wine fermentation; however, its presence during maturing or barrel-ageing can sometimes result in a reduction in the quality of wine by refermentation. In this work, we developed a quantitative real-time PCR (QPCR) for the rapid detection and quantification of S. cerevisiae in wine. The primers and the hydrolysis probe (TaqMan®) were designed from the sequence of a DNA fragment present only in S. cerevisiae and absent in other wine yeasts obtained from an RAPD-PCR analysis. The QPCR developed was highly reproducible, allowing the specific detection and quantification of this yeast in artificially contaminated wines, with a detection limit of 78 CFU/mL. Furthermore, the usefulness of the QPCR developed was evaluated through the quantification of the yeast in wine samples obtained from vineyards, confirming the quantitative capacity of the method. The methodology developed was specific, fast and a sensitive tool for the detection and enumeration of S. cerevisiae cells in wine.