Microbe used for biocontrol of pest butterfly caterpillars:

Bacillus thuringiensis produce endotoxin which when ingested and released in the gut of the larvae of insect pest, disrupts the insect gut lining thereby killing earthen. Related Theory Bacillus thuringiensis (Bt), is a grampositive soil bacterium. It forms Cry proteins during the stationary phase of its growth cycle. First, identify a strain of Bt that kills the targeted insect. Then isolate the gene that produces the lethal protein. That gene is removed from the Bt bacterium and is inserted into plant cells. Any plant cell that has the Bt gene must also have the resistance gene that was attached to it and grown or cultured. The modified plants produce the same lethal Bt protein produced by Bt bacteria because the plants now have the same gene.