Cider Apple Native Microbiota Characterization by PCR-DGGE

The surface microbiota of different recognized apple varieties used to elaborate a Protected Designation of Origin cider was studied to analyse the microbial diversity and its potential link to the microorganisms involved in the cider fermentation process. The V3 region of the bacterial 16S gene and the D1 domain of the eukaryotic 26S gene were amplified by polymerase chain reaction (PCR) and analysed by denaturing gradient gel electrophoresis (DGGE). The most intense bands found in the DGGE profiles were sequenced and compared with those in the GenBank database. The profiles showed a high microbial diversity, but little variation was found among the varieties. Identification of the bands showed that the usual species associated with an apple juice fermentation were not found, suggesting that the microorganisms responsible for spontaneous fermentation come from the equipment and the production environment.