A medium for the production of biopesticides (Bacillus sphaericus and Bacillus thuringiensis subsp. israelensis) in...

Chicken feathers, discarded as bioorganic wastes from poultry processing industries, are rich in keratin (structural protein). Deoiled rice bran (DRB), in contrast, is an agrowaste product consisting of protein, fiber, and carbohydrates. This study highlights a new medium for producing biopesticides from these bioorganic wastes, by culturing Bacillus sphaericus (Bs) and B. thuringiensis subsp. israelensis (Bti), to synthesize mosquitocidal toxins. Biochemical studies indicated that the amount of mosquitocidal spore/crystal toxins produced from the experimental culture medium (chicken feather waste [CFW] + DRB) is higher than that from the conventional medium (Nutrient Yeast Extract Salt Medium [NYSM]). The bacteria produced in these media (NYSM, CFW, DRB, and CFW + DRB) were bioassayed against mosquito vectors, and the toxic effect was found to be statistically similar (fiducial limits overlapping). Cost analysis based on the raw materials, indicated that, the use of CFW and DRB, as culture medium, is highly economical, for the industrial production of these mosquito pathogenic bacilli.