Optimization of medium composition for the production of mosquitocidal toxins from Bacillus thuringiensis subsp. israelensis

Optimization of chicken feather (CF) based culture medium for the production of Bacillus thuringiensis subsp. israelensis (Bti) biomass in combination with the agro industrial by-product (coconut cake, CC) and manganese chloride (MnCl2) has been evaluated. The biomass yield of Bti spore/crystal toxin was highest (12.06 g/L) from the test medium (CF+CC+MnCl2) compared to the reference medium (Luria Bertani, LB). Toxicity assay with Bti produced from the test medium against mosquito vectors (Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti) was also satisfactory and results were comparable with bacteria produced from LB. The results suggest that Bti can be produced to the maximum extent possible as a potential mosquitocidal activity as suggested by the test medium (CF+CC+MnCl2).