Molecular Mechanisms of Resistance to Heat and Oxidative Damage

Spore heat resistance can be predicted within reasonable limits from knowledge of optimal growth temperature of the sporeformer, the temperature of sporulation, water content of the spore protoplast, cortex size, total mineralization and specific mineralization. The molecular mechanisms by which dehydration and mineralization act to stabilize spores against heat damage are unknown. A major need for further progress is to identify the principal targets for lethal damage. In this review the hypothesis was explored that heat killing may be related to oxidative killing. The proposed common denominator for the two is the formation of radicals able to react with, and irreversibly damage, spore polymers such as proteins or DNA.