BIOCHEMICAL AND GENETIC-CHARACTERISTICS OF BACTERIOCINS OF FOOD-ASSOCIATED LACTIC-ACID BACTERIA

Numerous strains of lactic acid bacteria associated with food systems are capable of producing bacteriocins, or antibacterial proteins with activity against foodborne pathogens such as Listeria monocytogenes. S taphylococcus aureus, and Clostridium botulinum. Recently, considerabl e emphasis has been placed on the identification of these proteins and their biochemical properties, including spectrum of activity, product ion conditions, purification procedures, amino acid composition, amino acid sequence, and modes of action. Advances in genetic engineering t echniques have facilitated the characterization of these proteins at t he genetic level, providing information on hydropathic index, protein synthesis and structure, immunity determinants for resistance and/or t olerance, and cloning of bacteriocin genes into other organisms. Prior to the utilization of bacteriocins and/or die producer organism in fo od systems, a thorough understanding of the physical, biochemical, and genetic properties is required. Additional parameters for use of bact eriocins and bacteriocin-producing organisms in food systems also are discussed.