Genetic diversity of the pln locus among oenological Lactobacillus plantarum strains.

A total of 33 Lactobacillus plantarum strains obtained from grape musts and wines during alcoholic and malolactic fermentations were submitted to PCR analysis with specific primers directed to 27 genes of the plantaricin (pln) locus previously described for L. plantarum strains. The number of genes that were detected varied depending on the strain, and cluster analysis of results rendered seven groups, named plantaritypes (similarity within each group >89%) that included all the 33 oenological strains, four L. plantarum type strains (C11, NC8, J23 and J51) that had been previously described, and strain WCFS1 whose genome had been fully sequenced. The common features for most strains (74%) were the presence of the plnABCD regulatory system (which includes genes of the inducing peptide, its coupled membrane-located histidine protein kinase and two response regulators), the two-peptide bacteriocin plnEF genes and the genes of a membrane-bound ABC transport system. The pln locus is shown to be widespread among oenological strains (94% of appearance), as well as to possess a remarkable plasticity and variable regions related to its regulation and bacteriocin production.