Which enzyme in the midgut of insect is instrumental in the release of core toxic fragments from bacterial spores ingested by it?

Step-by-step solution

Bacillus thuringiensis produces proteinaceous toxins in an inactive form called protoxins. When an insect ingests these spores or crystals, the alkaline pH of the insect's midgut solubilizes the crystals. Subsequently, midgut proteinases (proteases) cleave the inactive protoxin into its active core toxic fragments. These active toxins bind to the surface of midgut epithelial cells, creating pores that cause cell swelling and lysis, eventually leading to the death of the insect. Answer: Proteinase