Question

The trigger for activation of toxin of Bacillus thuringiensis :

• A. Acidic pH of stomach
• B. High temperature
• C. Mechanical action in the insect gut
• D. Alkaline pH of gut

Answer 1

The correct option is D Alkaline pH of gut

Bt toxin protein exist as inactive protoxins but once an insect ingest the inactive toxin, it is converted into an active form of toxin due to the alkaline pH of the gut which solubilise the crystals. The activated toxin binds to the surface of midgut epithelial cells and create pores that cause cell swelling and lysis and eventually, cause death of the insect.

So, the correct answer is- Alkaline pH of gut.