Expression of Bacterial Toxin in Agriculture Using Molecular Biotechnology Techniques - Currently, the major weapons against the attackers of plants are chemical insecticides. But chemicals have some impact on the environment. Natural microbial pesticides, such as the species Bacillus thuringiensis (B t) have been used in a limited way for over 38 years. Upon sporulation, these bacteria produce a crystalized protein that is toxic to the larvae of a number of insects.

The toxic protein does not harm non susceptible insects and has no effect on vertebrates. The crystal protein is normally expressed as a large, inactive protoxin about 1200 amino acids in length and with a molecular weight of 1, 20,000 Dalton. The toxin acts by binding to receptors on the surface of mid gut cells and blocking the functioning of these cells. Research is on the way for commercial use.