[Mechanisms of the antibiotic activity of bacteriocins].
Some bacteria possesses the genetic capacity to synthesize compounds referred to as bacteriocins; such compounds are antagonic for other closely related bacteria by inhibiting bacterial growth. These toxic substances are either simple polypeptides or very complex macromolecules. However the feature of being a "killer" strain is coded by chromosomal or plasmid genes. The mechanism of lethal action is carried out either directly or indirectly against certain functions of the target cell; death of the sensitive strain is produced as a consequence of transport collapse at membrane level resulting in a drastic drop of indispensable metabolites or ions; in other cases the antibacterial effect produces blocking of macromolecule synthesis; or loss of metabolite stabilization within the cell altering the basic metabolism. Repercussions of bacteriocinogeny may be: use as epidemiological tool through bacteriocin-typing techniques; biological control by means of specific bacteriocins; regulation of bacterial growth rate in a population as a competence mechanism for a given ecological habitat; genetic transfer between competent cells; study of superficial receptor sites and its role in natural immunity; use as therapeutic agents through a number of problems like cross-toxicity and specificity of action still remain unsolved.
García-Quintana
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Instituto de Microbiología, Facultad de Ciencias Universidad Austral de Chile, Valdivia.
D001430:Bacteriocins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology
D001430:Bacteriocins
Mecanismos de la actividad antibiotica de bacteriocinas.