Background: The development of antibiotic resistance amongst bacterial pathogens and a
population explosion, e.g. in countries such as Indonesia, are two issues the world is facing today.
These issues have stimulated interest in the development of new antimicrobial therapeutic agents and
contraceptive strategies, such as novel spermicides. Bacteriocins, which are bacterially-derived antimicrobial
peptides, may fulfill some of the criteria for these new agents.
Methods: Weissella confusa MBF8-1, originally isolated from a homemade soy product, exhibits antibacterial
activity that was subsequently found to be plasmid-encoded, presumably by three peptides
Bac1, Bac2 and Bac3. In the present study, we tested cell-free MBF8-1 bacteriocin preparations and
chemically-synthesized versions of Bac1, Bac2 and Bac3 peptides for (i) its antibacterial activity
against the indicator bacterium Leuconostoc mesenteroides and (ii) its ability to affect the motility of
spermatozoa. Nisin, a known lantibiotic bacteriocin, was used as the control.
Results: Here, we demonstrate that synthetic Bac1, in combination with synthetic Bac2, was sufficient
to inhibit the growth of L. mesenteroides and affect sperm motility. However, the presence of all three
synthetic peptides, s-Bac1, s-Bac2 and s-Bac3, was required for full potency.
Conclusion: In summary, the bacteriocin-like peptides of W. confusa MBF8-1 have the potential to be
developed as a narrow-spectrum antimicrobial agent and a novel spermicidal agent.