Bacillus Calmette–Guerin (BCG) A nonvirulent form of Mycobacterium bovis that causes tuberculosis in cows. It was isolated By Calmette and Guerin and used as a vaccine against tuberculosis since 1928.
Bacillus subtilis A bacterium commonly used as a host in recombinant DNA experiments because of its ability to secrete proteins.
Bacillus thuringiensis (B.t) Naturally occurring soil bacterium that generates a crystalline protein, a product of the cry gene that is toxic to a variety of Lepidoptera but is harmless to animals and humans. Transgenic plants expressing the δ-endotoxin of Bacillus thuringiensis (B.t) have been created. The endotoxin gene is cloned into vectors and transferred into crop plants.
This enables the plants to produce the endotoxin in their tissues and kill insect pests. The endotoxins present in the inactive form are activated in the insect midgut. The active toxin binds to the receptors on the surface of the midgut causing ionic imbalance, cell burst, lysis and eventually death of the insect.


