bacteriocids

Bacteriocids are a diverse group of ribosomally synthesized proteinaceous toxins produced by bacteria to inhibit or kill closely related bacterial strains. They generally exhibit a narrow spectrum of activity and producers carry immunity mechanisms to avoid self-damage. Unlike broad-spectrum antibiotics, bacteriocids are encoded by specific gene clusters and often act only on nearby competitors.

In Gram-positive bacteria, bacteriocids include lantibiotics such as nisin and other small, non-modified peptides. In Gram-negative bacteria, colicins and microcins represent a distinct class. Bacteriocid genes are often located on plasmids or chromosomal loci and frequently include immunity and export genes.

Mechanisms vary: many bacteriocids disrupt target cell membranes, forming pores that lead to ion leakage and cell death; others have enzymatic activities that degrade nucleic acids or inhibit essential processes. Self-immunity proteins and dedicated secretion systems help producers avoid harm.

Applications include use as natural food preservatives, with nisin being the most widely used example approved in many countries. Research also explores bacteriocids as alternatives to traditional antibiotics and as biocontrol agents in agriculture and medicine, though clinical development faces challenges such as narrow activity and resistance.

Limitations and considerations: spectrum and resistance, stability in processing conditions, regulatory and safety assessments, and production costs. Despite these limitations, bacteriocids provide a targeted antimicrobial option with established utility in food safety and potential therapeutic value.