Abstract—

This is the first report on electron microscopic investigation of the effect of bacteriocin on Bacillus anthracis spores. The new bacteriocin, subtilosin P19, isolated from a natural Bacillus subtilis strain, effectively killed dormant B. anthracis spores at concentrations of 0.5‒35 µg/mL after 60-min exposure. Our data, combined with analysis of the known mechanisms of the action of bacteriocins, suggest that the mechanism of spore inactivation was apparently based on multiple disruptions of the integrity of the inner and outer membranes surrounding the cortex of the dormant spore. It is also likely that the molecular configuration of subtilosin P19 allows it to penetrate through the outer integuments and to damage the vital membrane structures of the anthrax spores. Subtilosin P19 can serve as a promising basis for new antimicrobial preparations of natural origin.