Possible involvement of gut-lumen bacteria in in-vivo proteolytic degradation of Bacillus thuringiensis δ-endotoxins

Abstract

Larval gu juice from aseptically reared beet armyworm, Spodoptera exigua, exhibited lowered processing activity towards the parasporal inclusion proteins of Bacillus thuringiensis as compared with that from normal larvae. Of the seven aerobic bacteria predominantly found in guts of normal larvae, a Bacillus isolate showed marked proteolytic activity against inclusion proteins. The results suggest the possible participation of gut‐lumen micro‐organisms in in‐vivo degradation and processing of B. thuringiensisδ‐endotoxins.