Environmental microbiology as related to planetary quarantine

The experimental design of a study to evaluate the effect of different cleaning methods and storage conditions on the dry heat resistance of Bacillus subtilis var. niger spores is described and the results for the first evaluation are reported. Specifically, the synergistic effect which occurs when spores are subjected simultaneously to dry heat and gamma radiation so as to be able to specify thermoradiation sterilization cycles was investigated. Attempts were made to understand the underlying mechanism(s) that lead to spore death from this combination of stresses. Data cover: (1) the survival of spores on surfaces at various temperatures in a precisely controlled environmental system, (2) the rate of destruction of these spores at ambient temperature when subjected to gamma radiation, and (3) the rate of destruction of spores when they are subjected to combined gamma radiation and thermal stresses