Molecular and Physiological Properties of Indigenous Strains of Oenococcus oeni Selected from Nero di Troia Wine (Apulia, Italy)

The characterization of Oenococcus oeni strains isolated from Nero di Troia wine (Apulia,Italy) sampled in two distinct production areas was carried out. The two indigenous populations,consisting of 95 and 97 isolates, displayed high genetic diversity when analyzed by amplifiedfragments length polymorphisms (AFLP). Based on the UPGMA dendrogram obtained by AFLPanalysis, the two populations displayed similar genotypes that grouped in the same clusters with ahigh level of similarity (>95%). One genotype was found in only one of the two areas. Representativestrains of each cluster were analyzed for their enzymatic activities (esterase, ?-glucosidase, andprotease), assayed in whole cells, and tested for their metabolic properties (consumption of L-malicacid, citric acid, acetaldehyde, and arginine) and growth parameters. Significant differences amongstrains, including the reference strain ATCC BAA-1163, were observed for all of these properties.Principal component analysis evidenced phenotypic differences among strains, and well separatedsome of them belonging to different genotypes. Strains exhibiting the best performances in most ofthese traits could be further investigated in order to select possible candidates as malolactic startersfor Nero di Troia wine. This study provided insights on the population structure of O. oeni of a localwinemaking area useful to the understanding of the regional diversity of this bacterium, an issue notyet completely resolved