Partial characterization of novel nematicidal toxins from Bacillus cereus Frankland and Frankland 1887 and their effect on root-knot nematode, Meloidogyne incognita(Kofoid& White) Chitwood

Abstract

Bacillus cereus isolated from the egg masses of root-knot nematode, MeIoidogyne incognita from tomato rhizosphere was grown in casein-peptone soy meal peptone (CASO) broth for partial characterization of toxins from cell-free filtrates. Cell-free culture filtrates of B. cereus at 72 hours of growth and beyond, reduced egg hatching (90'l"o) and caused 100 per cent mdrtality of juveniles in 4 hours of exposure, which coincided with the postsporulation phase (72h) of the bacterial growth indicating profound toxicity during and after the sporulation phase. The native PAGE electrophoresis of the partially purified cell-free culture fiitrates showed that 3 bands of::::: 15, 40 and 60 kDa appeared in 72, 84 and 96 hours of growth, respectively, coinciding with post-sporulation phase of the bacterium.