NOVEL BACILLUS-THURINGIENSIS SEROVAR AIZAWAI STRAINS ISOLATED FROM MULBERRY LEAVES IN INDONESIA

Bacillus thuringiensis isolates have been recovered from numerous sour ces, including soil, grain dust, plant leaves, diseased insect larvae from insectaries, and sericulture environments. During a study of B. t huringiensis isolated from mulberry leaves from Indonesia, we found tw o serovar aizawai isolates. One of the serovar aizawai isolates (Bun 1 -14), which was a crystal consisting mainly of 69 kDa peptides, exhibi ted mosquitocidal activity, while another isolate (Bun 2-1) did not. B oth isolates were analyzed by PCR. Although these isolates produced pr oteinaceous crystals, no cry genes, known as cryI, cryII, cryIII and c ryIV, were detected. It appears these strains contain novel cry genes that are responsible for the unique insecticidal activity.