The influence of recovery media on thermal resistance values of spores of a Putrefactive Anaerobic Bacterium.

Yesair's pork infusion medium, as modified by Wynne and Foster (1948), has been extensively employed in thermal resistance studies of spores of Clostridium species. While this medium is excellent for the recovery of spores of these organisms, it is expensive and laborious to prepare. Recent unpublished data in this laboratory have demonstrated that counts of heat-activated spores of Putrefactive Anaerobe (P.A.) No. 3679 made in Eugonagar (B.B.L.) are higher than those made in Yesair's medium. In view of these results, a comparative study of various media for recovery of severely heat-treated spores of Putrefactive Anaerobe 3679 was carried out. Since this organism is widely used in the food industry