The effects of agitation, sediment, and competition on the persistence and efficacy of Bacillus thuringiensis var. israelensis (Bti).

The persistence and efficacy of Bacillus thuringiensis var. israelensis (Bti) were examined in aquatic microcosms under varying conditions of agitation, sediment content, and microbial competition. Agitation was found to be the most important factor in maintaining persistence of Bti cells and the bioavailability of Bti toxin. Sediment acted to decrease efficacy by increasing settling of the toxic particles, but did not decrease the persistence of Bti cells were found, but efficacy of the Bti endotoxin was adversely affected.