Effect of brine composition on yeast biota associated with naturally fermented Nocellara messinese table olives.

The study aims to assess the yeast biota associated with table olives of the cultivar Nocellara messinese naturallyfermented using different brines. Microbial counts, physico-chemical parameters, and yeast consortia wasevaluated at days 0, 3, 7, 15, 30, 60, 90, 180, and 240. Yeasts were identified by PCR-RFLP of the 5.8S ITS rRNAregion and sequencing of D1/D2 domain of the 26S rRNA gene. At the fermentation end, the yeast populationwas assessed by PCR-DGGE analysis. Throughout the eight months of fermentation, the brine modificationdetermined different evolution of the yeast species. The salt concentration shift from 5% to 8% delayed thegrowth of some species at the end of the fermentation. The experimental brine acidification determined a growthof Pichia mexicana and Saccharomyces cerevisiae that were not found in the other brine formulations. Pichiakudriavzevii was the most isolated species followed by Wickeramomyces anomalus, Zygoascus hellenicus, Candidaboidinii, Saccharomyces cerevisiae, Candida aaseri, Candida tropicalis, Candida diddensiae, Zygoascus meyerae, andPichia mexicana. P. kudriavzevii and W. anomalus species were present in all the processed olives. Some of thestrains exhibited suitable technological properties so they could be good candidates as starter in table olivefermentations.