Directed killing of anthrax spores by microwave-induced cavitation

High-power pulsed-microwave radiation damages anthrax spores by apparent sonoluminescence in aqueous solutions containing the organic semiconductor diazoluminomelanin (DALM). DALM biosynthesized by JM109 E. coli, containing the plasmid pIC2ORNR/sub 1.1/, had a higher affinity for spores of Sterne strain anthrax when compared to several other species of bacilli and enhanced the effect. Upon exposure to pulsed-microwave radiation, anthrax spores showed a maximum of 4 to 5 (i.e., 4.6) logs of kill. The light emitted was typical of plasma gas emissions and the spores, upon scanning electron-microscopic examination, showed enlargement and rupture typical of rapid expansion. Therefore, microwave-induced cavitations localized to the spore surfaces enhanced kill.