The bacteriocins produced by lactic acid bacteria have gained much attention as potentially useful food additives against food-borne pathogens. One bacteriocin, nisin was the first bacteriocin derived from fermentation of a lactic-acid bacterium and was approved by the FDA in April 1989 to prevent the growth of botulism spores in pasteurized process-cheese spreads. Nisin does not inhibit Gram-negative organisms, yeasts or fungi, but does inhibit most Gram-positive organisms including spore-formers such as Clostridia botulinum and heat-resistant spoilage organisms. Lactic acid bacteria and their byproducts are currently present in many of the foods we consume. For this reason, they are regarded as safe and natural by consumers. Metabolic byproducts of lactic acid bacteria have been shown to inhibit the growth of several important pathogens, and increase shelf life beyond current "chemical" preservatives. Because lactic acid bacteria already preserve foods such as cheese and milk, it makes sense to try and inoculate them into other foods as well. Besides being less potentially toxic or carcinogenic than current antimicrobial agents, lactic acid bacteria and their byproducts have been shown to be more effective and flexible in several applications. |
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