• S. Revathi
• Dr. N.Vanitha
• D. K. Harish

Bacillus thuringiensis (Bt) is a widespread bacterium known for producing multiple proteins with toxicity against various invertebrates, including insects, nematodes, mites, and certain protozoans. The potential of Bt to be used as an insecticide was recognized in the early twentieth century and since that time many Bt-based biopesticides have been commercialized. Our research focused on soil samples from various agricultural fields in Erode, covering crops such as paddy, mango, maize, groundnut, sweet potato, turmeric, banana, chilly, green leaf, and sugar cane.The samples were inoculated on T3 agar plates, resulting in the formation of colonies. T3 agar, functioning as a selective medium for Bt, facilitated the observation of colony morphology, which exhibited characteristics such as circular, white, flat, undulate, or entire. The research revealed that all organisms under study demonstrated the production of spherical-shaped spores and crystals also. Bt, identified as a Gram-positive, rod-shaped bacterium, was found to be prevalent in soil. The strain of Bt was isolated from soil, efficacy was tested against silkworms, Bombyx mori. The mortality of Bt against silk worms after 3 days was 70%, respectively. Insecticidal crystal protein profile of Bt produced 97, 68, 43, 29, 20 and 14 kDa bands. The results clearly established the potent insecticidal properties of the Bt strain, suggesting its potential application in disease control through the targeting of insect vectors.

Crop soil, Bacillus thuringiensis, Characterization, Insecticidal activity, Silkworm

"Isolation and Characterization of Bacillus thuringiensis from Crop soil and Evaluation of toxicity on Bombyx mori", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.11, Issue 1, page no.f224-f231, January-2024, Available :http://www.jetir.org/papers/JETIR2401527.pdf

"Isolation and Characterization of Bacillus thuringiensis from Crop soil and Evaluation of toxicity on Bombyx mori", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.11, Issue 1, page no. ppf224-f231, January-2024, Available at : http://www.jetir.org/papers/JETIR2401527.pdf