Classification and mode of action of membrane-active bacteriocins produced by gram-positive bacteria.

Bacteriocins are ribosomally synthesized antimicrobial peptides produced by microorganisms belonging to different eubacterial taxonomic branches. Most of them are small cationic membrane-active compounds that form pores in the target cells, disrupting membrane potentials and causing cell death. The production of small cationic peptides with antibacterial activity is a defense strategy found not only in bacteria, but also in plants and animals. Bacteriocins are classified according to different criteria by different authors; in this review, we will summarize the principal bacteriocin classifications, highlight their main physical and chemical characteristics, and describe the mechanism of some selected bacteriocins that act at the membrane level.