Interest in novel biological preservation methods has increased during recent years, supported by research indicating that antagonistic microorganisms or their antimicrobial metabolites may have some potential as natural preservatives to control the growth of pathogenic bacteria in foods, and also to control mycotoxinogenic fungi. To date, nisin is the only bacteriocin that has found practical application in some industrially processed foods. Many other bacteriocins from lactic acid bacteria have recently been characterized, but their efficacy in foods has not been studied extensively. Better understanding of the interactions between antimicrobial metabolites and food components is necessary to evaluate their potential as preservatives.