Characterization of salivaricin CRL 1328, a two peptide bacteriocin produced by Lactobacillus salivarius CRL 1328 isolated from the human vagina.

VERA PINGITORE, E.; HEBERT, E.M.; NADER, M.E.; SESMA, F.

RESEARCH IN MICROBIOLOGY

ELSEVIER SCIENCE BV

Año: 2009 vol. 160 p. 401 - 408

0923-2508

Salivaricin CRL 1328 is a heat-stable bacteriocin produced by Lactobacillus salivarius CRL 1328, a strain isolated from healthy human vagina, with potential applications to prevent urogenital infections. The objective of this study was to characterize the locus responsible for salivaricin CRL 1328 production, and its mechanism of action against E. faecalis MP97 as sensitive strain.Oligonucleotides were designed based on sequences of antimicrobial peptides previously described in the literature. The salivaricin CRL 1328 cluster was identified, sequenced and analyzed. This cluster was similar to the previously described ABP118 which codified for a two peptide bacteriocin. The putative mature peptides of salivaricin CRL 1328, Salα and Salβ, were chemically synthesized. These peptides did not show bacteriocin activity assayed individually. Both peptides exhibit the optimal antimicrobial activity at an equimolar ratio.Spectroscopic fluorescence assays were carried out by using the synthetic peptides in order to study the effect of salivaricin on the proton motive force. This bacteriocin showed to dissipate the membrane potential and the transmembrane proton gradient, both components of proton motive force.E. faecalis MP97 cells treated with salivaricin CRL 1328 peptides were observed through transmission electron microscopy showing ultrastructural modifications