Comparative sensitivity to UV-B radiation of two Bacillus thuringiensis subspecies and other Bacillus sp.
Susceptibility of Bacillus thuringiensis spores and toxins to the UV-B range (280--330 nm) of the solar spectrum reaching Earth's surface may be responsible for its inactivation and low persistence in nature. Spores of the mosquito larvicidal B. thuringiensis subsp. israelensis were significantly more resistant to UV-B than spores of the lepidopteran-active subsp. kurstaki. Spores of subsp. israelensis were as resistant to UV-B as spores of B. subtilis and more resistant than spores of the closely related B. cereus and another mosquito larvicidal species B. sphaericus. Sensitivity of B. thuringiensis subsp. israelensis spores to UV-B radiation depended upon their culture age; 24-h cultures, approaching maximal larvicidal activity, were still sensitive. Maximal resistance to UV-B was achieved only at 48 h.
Myasnik
M
M
Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Be'er-Sheva 84105, Israel.
Manasherob
R
R
Ben-Dov
E
E
Zaritsky
A
A
Margalith
Y
Y
Barak
Z
Z
D001407:Bacillus / Q000737:chemistry / Q000235:genetics / Q000528:radiation effects*; D001413:Bacillus thuringiensis / Q000737:chemistry / Q000235:genetics / Q000528:radiation effects*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000032:analysis; D001427:Bacterial Toxins; D004731:Endotoxins / Q000032:analysis; D006460:Hemolysin Proteins; D010957:Plasmids; D012808:Sigma Factor; D013045:Species Specificity; D013171:Spores, Bacterial / Q000737:chemistry / Q000235:genetics / Q000528:radiation effects; D014157:Transcription Factors; D014466:Ultraviolet Rays
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D012808:Sigma Factor; D014157:Transcription Factors; C030956:insecticidal crystal protein, Bacillus Thuringiensis; C092468:spoIIR protein, Bacillus subtilis; C030069:spore-specific proteins, Bacillus