INTERACTIONS OF FOOD STARTER CULTURES AND FOOD-BORNE PATHOGENS: THE ANTAGONISM BETWEEN STREPTOCOCCUS LACTIS AND SPOREFORMING MICROBES

Lactic acid bacteria hinder development of sporeformers by production of acids, peroxides, and antibiotics. One of the best known of these antibiotics is nisin which is produced by Streptococcus lactis and is a permitted food additive in many countries. This paper traces the history of nisin, its effect in milk, cheese, processed cheese, canned, and other foods. Nisin primarily affects gram-positive bacteria but some of these produce nisinase, an enzyme which inactivates it. The preservative effect of nisin in heat treated foods is probably related to the retention of nisin on sporecoats. Nisin affects outgrowth of spores but not spore germination.