Comparison Study Of Toxicity Bacillus thuringensis from Soil Isolate and Mulberry Leaves in Indonesia

Background and Objective: Most strains of B. thuringiensis produce delta-endotoxin crystals toxic to lepidopteran insects such moth. But some strains of B. thuringiensis produce delta-endotoxin crystals toxic to dipteran insects such as mosquitoes and blackflies. To compare B. thuringiensis isolate from soil and mulberry leaves. Material and Methods:One gram of soil samples was suspended in 9 ml of sterile distilled water and shaken for 5 min. the upper layer of the soil suspension was transferred to a test tube and heated at 80°C for 5 min in water bath to kill non-spore-forming organism and vegetative cells to prepare the sporulated culture, bacteria were grown on nutrient agar pH 7.2, at 30°C for 4 days. The isolates were obtained from mulberry leaves collected in West Java, Indonesia, using the leaf-lift technique. Leaves were trimmed to fit inside a 100 mm petri dish. Abaxial leaf surfaces were placed in contact with nutrient agar, and a sterile, per forated stainless steel disk was placed on the leaf sections to ensure maximum contact with the agar. After the sample was coated with carbon and gold, it was observed and photographed with (SEM). However they had differences form crystal protein, but they had unique as insecticidal to control the same orders (mosquitocidal). Results:The study found that B. thuringiensis serovar entomocidus INA288 produced large cuboidal-form crystals and B. thuringiensis serovar aizawai BUN 1-14 a little homology with serovar entomocidus INA288 but, B. thuringiensis israelensis ONR60A has irregular shaped crystal protein. Toxicity results that serovar entomocidus INA288, serovar aizawai BUN 1-14 and serovar israelensis ONR60A showed toxic to mosquito insects. which was composed of major protein of 130 kDa peptides. B. thuringiensis serovar entomocidus INA288 has 70 kDa and aizawai BUN 1-14 had 69 kDa. Conclusion: B. thuringiensis strain had different crystal protein form but had same toxicity.