Protein Patterns and Larvicide Activity of Crystalline Inclusions of Bacillus thuringiensis ssp . kumamotoensis DSM 6070

Abstract

Morphological and electrophoretic analysis of the c rystalline inclusions (parasporal crystals) of sporulated cultures of B. thuringiensis ssp. kumamotoensis DSM 6070 (Bt 6070) was conducted via phase contrast and scanning electron microscopy and sodium dodecyl sulphate-polyacrylamide gel electrophoresis . The activity of the spore-crystal suspensions against house fly ( Musca domestica ) larvae was also assessed. Bipyramidal and smaller, irregular shaped crystals were observe d in the sporulated cultures. 130, 75 and 25 kDa bands were detected in the protein patte rn. The presence of 25 kda proteins in Bt6070 has not been reported earlier. The spore-cry stal suspension showed significant larvicide activity against housefly larvae. Larvici de activity of B. thuringiensis ssp. kumamotoensis against any dipteran species has not been detected yet. Further studies are needed on identifying the dipteran- active fraction . Keywords : Bacillus thuringiensis, Parasporal crystals, Polyacrylamide gel-electrophor esis, Scanning electron microscopy.