bakteriocyn

Bakteriocyn is a ribosomally synthesized antimicrobial peptide produced by bacteria. It functions to inhibit or kill other bacteria, often displaying a narrow spectrum that targets closely related species. Bakteriocyns are produced by a wide range of bacteria, with lactic acid bacteria being among the most well studied sources.

Bakteriocyns are typically encoded by dedicated gene clusters carried on plasmids or chromosomes. They are usually produced as precursor peptides with leader sequences, then processed and secreted by dedicated transport systems. The genes often include immunity determinants that protect the producing strain from its own bacteriocin. Many bacteriocins are small, heat-stable peptides, though larger proteins exist in some classes.

Classification of bacteriocyns commonly distinguishes between lantibiotics (class I), which contain unusual amino acids produced by post-translational modifications (for example, nisin and subtilin), and non-modified peptides (class II, such as pediocin and lacticin). There are additional groups for larger, non-peptide bacteriocins. Their modes of action vary but many disrupt the target cell’s membrane integrity, forming pores and dissipating the proton motive force. Some, such as certain lantibiotics, also bind lipid II to inhibit cell wall synthesis.

Applications of bacteriocyns include food preservation and safety, where they act as natural preservatives to inhibit spoilage and pathogenic bacteria. Nisin, for instance, is widely used as a food additive and has regulatory approvals in several regions. Beyond food, bacteriocyns are explored for therapeutic use and as alternatives or adjuncts to traditional antibiotics, though challenges remain in delivery, stability, and resistance management.