Biodiversity of Oenococcus oeni strains isolated from wine produced in Apulian region

In this work, we analyse the biodiversity of O. oeni strains isolated from wine produced in Apulia region and undergoing spontaneous malolactic fermentations. Our attention was focused on ther genetic biodiversity of O. oeni strains and on their different efficiency in degrading malic acid. For genotypic characterization we utilized variable number tandem repeat (VNTR), a techniques successful used in literature for molecular typing of O. oeni strains. VNTR approach is based on the presence of a variable number of tandem repeats (TR) at a specific locus in the genome of a microorganism. Analyzing 50 strains isolated from different wines, VNTR identified 31 profiles, of which 11 unique profiles. Variations in the TR regions directly induce changes at the genetic level in the DNA molecule itself. These changes impact the genetic repertoire of a given microorganism and may play a role in the evolution of the species. This study confirmed the worldwide presence of two O. oeni phylogenetic subpopulations (A and B). All the strains have been screened for their capacity of degrading malic acid, bacteria were inoculated with two different times of inoculum, either together with yeast (coinoculum) or after the completion of alcoholic fermentation (sequential inoculum). Our aim is to study the natural biological diversity of O. oeni of specific a terroir to select strains suitable for of autochthonous malolactic starter cultures design.