Meat-model system development for antibacterial activity determination.
Bacteriocins are antibacterial substances produced by many different bacterial species. Although the bacteriocins form a heterogenous group with respect to production of bacteria, antibacterial spectrum, mode of action, and chemical properties, they are by definition proteinaceous compounds that are bactericidal toward organisms taxonomically close to the producer. The ability of lactic acid bacteria (LAB) to compete and finally dominate in mixed fermentations has been attributed to the production of several antimicrobial metabolites such as organic acids, carbon dioxide, hydrogen peroxide, diacetyl, and bacteriocins. The antimicrobial activities of the LAB have long been known, but their bacteriocins have received limited attention until recently. Numerous strains of lactic acid bacteria associated with food systems are capable of producing bacteriocins, or antibacterial proteins with activity against foodborne pathogens and contaminants. Recently, considerable enphasis has been placed on the physicochemical, biochemical, and genetic characterization of these proteins. Many methods for the detection of bacteriocin production as well as the determination of the potency of bacteriocin preparations have been described. All the usual techniques are based on the fact that bacteriocins can diffuse in solid or semisolid culture media, which are subsequently inoculated with a suitable indicator strain. This method has long been shown to have a good perfomance in the characterization of new bacteriocins. Although results obtained from broth systems show that bacteriocins inhibit target organisms, applied studies must be performed to confirm their effectiveness in food. As many lactic acid bacteria associated with meat products were described to be important natural bacteriocin producers, it has been necessary to assay their inhibitory efficacy in meat or meat products. Because of the complexity of these kinds of foods a simplified meat-model system was developed to determine the inhibitory activity of a bacteriocin.
Vignolo
Graciela
G
Centro de Referencia para Lactobacilos-CONICET, Tucumán, Argentina.
Castellano
Patricia
P
D000818:Animals; D001419:Bacteria / Q000254:growth & development* / Q000302:isolation & purification; D001430:Bacteriocins / Q000032:analysis* / Q000302:isolation & purification; D001431:Bacteriological Techniques; D008460:Meat / Q000382:microbiology*
D001430:Bacteriocins