The effect of certain sporulation conditions on the thermal death rate of Bacillus coagulans var. thermoacidurans.

One of the fundamental properties of spores which is of paramount interest to the food microbiologist is their extraordinary thermal resistance. In the canning of food products, the commercial thermal process, in order to be successful, must rid the product completely of the spores of Clostridium botulinum, and nearly so of all other types commonly associated with the raw material or encountered on the processing equipment. The basic experimental work necessary to establish a thermal process for a given food includes a determination of the thermalresistance of the resistant microorganism of significance in that food product. The mode of and the factors affecting the thermal resistance of a given type of spore must be comprehended and appreciated before a final and reliable thermal process can be established. Among these factors are the environmental conditions which prevail during growth and sporulation. The literature encountered is, in this respect, relatively uninformative and has covered only a limited number of spore-forming species. Neither the methods nor the results are in reasonable agreement; in many cases methods are not highly precise, and inferences have been based upon results which were neither adequately replicated nor properly analyzed. Furthermore, most of the food thermobacteriologists produce their spore crops for the thermal death rate determinations, under arbitrary laboratory conditions overlooking the effect which such conditions might have on the thermal death rate of the spores produced. Baillus coagulans var. twmoacidurans is an important food spoilage organism and has caused the tomato juice industry a considerable