A peptide or protein produced by bacteria that inhibits or kills closely related species or similar strains of the same species. Bacteriocins are more specifically targeted than antibiotics, serving to enhance the survival of the producing cell at the expense of genetically similar but distinct competitors. They are often encoded by plasmids, and traditionally were named according to the organism producing them. Hence, strains of Escherichia coli produce colicins, whereas Bacillus subtilis synthesizes subtilisins. Some form channels in the cell membrane of the target organism, allowing leakage of ions, whereas others act as nucleases, cutting DNA or RNA inside the cell. Bacteriocins produced by lactic acid bacteria include lantibiotics and pediocins; these are useful in the food industry for their activity against food spoilage organisms and pathogenic Listeria bacteria.