African Journal of Biotechnology Vol. 6 (13), pp. 1587-1591, 4 July 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Ecology and diversity of Bacillus thuringiensis in soil environment

Chatterjee, S. N.¹, Bhattacharya, T.², Dangar, T. K.³ and Chandra, G.¹

¹Microbiology Research Unit, Parasitology Laboratory, Department of Zoology, Burdwan University, Burdwan-713104. W.B., India.

²Department of Zoology, Vidyasagar University, Midnapore-721102, WB, India.

³Microbiology Laboratory, Central Rice Research Institute, Cuttack, India.

*Corresponding author. E-mail: soumen_microbiology@redi-ffmail.com.

Accepted 29 November, 2006

Bacillus thuringiensis populations ranged between 4.23 x 10⁵, 6.52 x 10⁵ cfu/g soil and consist of 11 types of isolates with 3 polymorphic, 7 spherical and 1 bipyramidal type of crystals. Polymorphic crystal containing isolates were further characterized. B. thuringiensis isolates were circular, white, flat and undulate or entire. These were gram-positive. These tolerated 5% NaCl and failed to grow anaerobically. None of these were positive for indole production. All were sensitive to streptomycin, vancomycin, polymyxin B and norfloxacin but resistant to penicillin G and ampicillin/sulbactum. All of the isolates were crystal forming rods, width of rods was >0.9 um, catalase positive and sporangia were not swollen. All of the isolates hydrolyzed protein but only BTc 175 produced arginine dihydrolase, BTc 152 and BTc 175 produced urease.

Key words: Bacillus thuringiensis, soil, isolates, polymorphic crystal.