What triggers the activation of protoxin to active toxin of Bacillus thuringiensis in boll worm?
(a) Acidic pH of stomach
(b) Body temperature
(c) Moist surface of midgut
(d) Alkaline pH of gut
Answer (d) : Some strains of Bacillus thuringiensis produce proteins that kill certain insects such as lepidopterans and dipterans. B. thuringiensis forms protein crystals during a particular phase of their growth. These crystals contain a toxic insecticidal protein which exists 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 solubilises the crystals.
