Mechanistic Studies of Spore Killing Using Variable Frequency Microwaves

The overall objective of this proposal is to characterize the molecular mechanism by which variable frequency microwave technology (VFM) inactivates bacterial spores. The long-term practical goal is to produce a device capable of eliminating contamination by microbial/viral/biological based biological warfare bioterrorism agents. Considerable scientific uncertainty exists regarding the molecular mechanisms of spore killing by microwaves. Hence, the immediate goal of this project is to study the mechanisms of VFM spore inactivation at the molecular level. To accomplish our objective the kinetics of inactivation of simulant spores derived from B. subtilis will be determined using VFM technology and compared to that of dry heat using a variety of solid surfaces which differ in their absorbance of microwave energy. In addition, the level of applied microwave power will be correlated with kill kinetics. Because DNA damage is a likely target for microwave induced damage, a search will be made for specific mutations in spore DNA. Such mutations are known to correlate with previously characterized modes of spore killing.