Cost-effective medium for the production of mosquitocidal toxins from a novel strain Bacillus thuringiensis subsp. israelensis/tochigiensis (H14/H19)

Shankar, Prabakaran, Manonmani Am
2016 European Journal of Biotechnology and Bioscience Online   unpublished
An indigenous isolate of Bacillus thuringiensis sharing the antigens of israelensis/tochigiensis was for the first time reported to exhibit mosquito larvicidal activity. In this study a cost effective medium using peanut milk was developed for production of the mosquitocidial endotoxin for this strain. Shake flask experiments were conducted using 2.5%, 5.0% and 7.5% of peanuts and compared with the conventional medium for biomass production, spore count and mosquitocidal activity. In stationary
more » ... vity. In stationary phase of growth, Peanut milk medium 5% gave dry cell mass yield of 3.14 g/L, spore count of 1.5 x 10 9 CFU/ml and mosquito larvicidal activity (LC50) of 0.010 µg/ml against late third instar larvae of Culex quinquefasciatus by 18 h as against the dry cell mass yield of 2.40 g/l, spore count of 1.2 x 10 9 CFU/ml and mosquito larvicidal activity (LC50) 0.007 µg/ml obtained using 24 h old culture of the conventional Nutrient yeast Extract Salt Medium (NYSM).