Novel Fermentation media for the production of mosquito pathogenic bacilli in mosquito control

Human industrial activities, inevitably, generate industrial wastes, consisting of, inorganic and organic materials, discharged from factories, fisheries, poultries and food processing industries. Degrading or handling these wastes, as unused disposals, without acquiring any additional benefits has led to an idea to develop a suitable technology to utilize bio-organic wastes. Chicken feathers have been discarded in bulk as waste from poultry processing industries, poultry farms and shops, globally. They normally accumulate structural proteins (keratins) that are resistant to biodegradation. Deoiled rice bran is also an agricultural waste which contains protein, fibre and carbohydrate content. Considering the abundant supply of these bioorganic wastes, we have successfully produced the biopesticides by culturing Bacillus sphaericus (Bs) and B. thuringiensis serovar israelensis (Bti) strains to synthesize mosquitocidal toxins. Biochemical studies indicate that the mosquitocidal spore/crystal toxins produced from the experimental culture medium (bird feather waste, BFW cum de-oiled rice bran, RBW) are higher than the conventional medium (Nutrient Yeast Extract Salt Medium, NYSM). The bacteria produced in these media (NYSM and BF, RB, RB+BF) were bioassayed against the mosquito vectors (Culex quinquefasciatus, Anopheles stephensi, Aedes aegypti) and the toxic effect was found to be the highest for the combination medium (BF+RB). Cost-effective analysis indicates that the use of bird feather waste and deoiled rice bran waste as culture medium is highly economical for the industrial production of these mosquito pathogenic bacilli. This study is, therefore, very important as it possesses the dual benefit of effective utilization of bio-organic waste materials from the environment and for the production of mosquitocidal biopesticides as well.