Insecticidal, antimicrobial, and antiviral activity of Bacillus thuringiensis ssp. kurstaki strains isolated from atmospheric aerosols in the South of Western Siberia

The data on insecticidal, antimicrobial, and antiviral activity of Bacillus thuringiensis ( Bt ) strains isolated in the microbiological study of height and ground atmospheric aerosol samples taken in the South of Western Siberia are presented. Among 36 isolated bacteria determined as related to the Bt species, 15 strains were relegated to the Bt ssp. kurstaki subspecies by results of intraspecific testing and studied for the presence of antagonistic attributes. In spite of long wandering in extreme conditions in the composition of atmospheric aerosols, including higher atmospheric layer (up to 7 km), the isolated Bt ssp. kurstaki strains keep high (inherent to this subspecies) entomopathogenic activity, possessed the ability to inhibit the multiplication of such pathogenic microorganisms as Staphylococcus aureus, Salmonella thyphimurium, Shigella sonnei, Candida albicans , and others, and manifested the ability to effectively neutralize the multiplication of the A/chicken/Kurgan/05/2005 (A/H5N1) avian influenza virus and A/Aichi/2/68 (A/H3N2) human virus. Properties of Bt strains isolated from atmospheric aerosols not only verified their well-known resistance to unfavorable factors of the environment but also exhibited the possibility of using them for developing viricides.