The locus responsible for production of plantaricin S, a class IIb bacteriocin produced by Lactobacillus plantarum LPCO10, is widely distributed among wild-type Lact. plantarum strains isolated from olive fermentations.

The genes plsA and plsB encoding for production of plantaricin S (Pls), a two-peptide bacteriocin produced by Lactobacillus plantarum LPCO10, are commonly distributed among wild-type Lact. plantarum strains isolated from olive fermentations. Among 68 independent isolates from different olive processing plants in South Spain, 15 of them were shown to produce bacteriocins that were active against other lactic acid bacteria, as well as spoilage and pathogenic bacteria. On the basis of PCR amplification and hybridization with specific probes, the Pls operon was detected in all the bacteriocin producer strains but not in the non-producer ones. Purification and subsequent amino acid sequencing of the bacteriocin produced by some of the 15 isolates yielded both the alpha and beta peptides from Pls. These results suggest that bacteriocin production contributes an ecological advantage for the wild-type Lact. plantanum strains in the colonization of the spontaneous, traditional olive fermentation process.