Inhibition of Clostridium botulinum and molds in aged, surface ripened cheese.

In the past fifty years, no recorded case of botulism has been attributed to surface ripened cheese (NIeyer and Eddie, 1950). When cheese spread was prepared from one type of surface ripened cheese, botulinum toxin was demonstrated in only one out of several million jars (Dauer, 1952). The fact that botulism was never observed with the original surface ripened cheese from which cheese spreads were made may be because, in the preparation of cheese spreads, the natural microbial flora is altered by heat. Subsequently, the heat resistant spores of Clostridium botulinum may germinate and produce toxin (Wagenaar and Dack, 1958). The purpose of this investigation is to search for a growth inhibiting factor(s) for C. botulinum and certain molds in types I and III surface ripened cheeses.'