Culture independent analyses and wine fermentation: an overview of achievements 10 years after first application

Wine fermentations are complex microbial ecosystems, with both yeasts and bacteria taking part in the transformation process with their metabolic activities. Traditional microbiological methods do not allow a complete understanding of the microbial ecology of complex systems. This is due mainly to the capacity of certain microorganisms to grow on microbiological media preferentially with respect to others. Moreover, with these methods, stressed or damaged cells cannot be detected on the plates. In the last 10 years new methods based on the analysis of nucleic acids (DNA and RNA) extracted directly from the sample without the need for microbial cultivation have been developed. A method often used in this type of study is the polymerase chain reaction (PCR) coupled with denaturing gradient gel electrophoresis (DGGE). This paper aims to report the most important contributions of PCR-DGGE to the study of microbiological ecology during wine fermentation.