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

Bacillus cereus isolated from the egg masses of root-knot nematode, Meloidogyne 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%) and caused 100 per cent mortality of juveniles in 4 hours of exposure, which coincided with the post-sporulation 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 filtrates 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.