Although when UV-irradiated seven most toxic strains of Bacillus sphaericus
lost their viabilities between 2.5-4.5 min, their larvicidal activity was
protected for longer periods. Benzaldehyde, cinnamaldehyde, salicylaldehyde
, methylene blue and yeast extract showed good protective effect for spore
viability and larvicidal activity from UV inactivation in B. sphaericus. Th
is protective effect has also been confirmed by SDS-PAGE analyses whereby t
he 42 kDa and 51 kDa toxic proteins bands did not disappear following UV tr
eatment.