Novel Bacillus thuringiensis serovar aizawai strains from nulberry leaves in Indonesia

Abstract

Bacillus thuringiensis isolates have been recovered from numerous sources, including soil, grain dust, plant leaves, diseased insect larvae from insectaries, and sericulture environments. During a study of B. thuringiensis isolated from mulberry leaves from Indonesia, we found two serovar aizawai isolates. One of the serovar aizawai isolates (Bun 1-14), which was a crystal consisting mainly of 69 kDa peptides, exhibited mosquitocidal activity, while another isolate (Bun 2-1) did not. Both isolates were analyzed by peR. Although these isolates produced proteinaceous crystals, no cry genes, known as cryI, cryII, cryIII and cryIV, were detected. It appears these strains contain novel cry genes that are responsible for the unique insecticidal activity. Key words: Bacillus thuringiensis, serovar aizawai, mulberry leaf, mosquitocidal