Characterization and technological properties of Oenococcus oeni strains from wine spontaneous malolactic fermentations: a framework for selection of new starter cultures

Aims: To characterize the genetic and phenotypic diversity of 135 lactic acidbacteria (LAB) strains isolated from Italian wines that undergone spontaneousmalolactic fermentation (MLF) and propose a multiphasic selection of newOenococcus oeni malolactic starters.Methods and Results: One hundred and thirty-five LAB strains were isolatedfrom 12 different wines. On the basis of 16S amplified ribosomal DNArestriction analysis (ARDRA) with three restriction enzymes and 16S rRNAgene sequencing, 120 O. oeni strains were identified. M13-based RAPD analysiswas employed to investigate the molecular diversity of O. oeni population.Technological properties of different O. oeni genotypes were evaluated insynthetic medium at increasing selective pressure, such as low pH (3Æ5, 3Æ2and 3Æ0) and high ethanol values (10, 11 and 13% v ⁄ v). Finally, themalolactic activity of one selected strain was assessed in wine by malolactictrial in winery.Conclusions: The research explores the genomic diversity of wine bacteria inItalian wines and characterizes their malolactic metabolism, providing an efficientstrategy to select O. oeni strains with desirable malolactic performancesand able to survive in conditions simulating the harsh wine environment.Significance and Impact of the Study: This article contributes to a betterunderstanding of microbial diversity of O. oeni population in Italian wines andreports a framework to select new potentially O. oeni starters from Italianwines during MLF.