A novel cost-effective medium for the production of Bacillus thuringiensis subsp. israelensis for mosquito control.

Bacillus thuringiensis subsp. israelensis (Bti) has been used for mosquito-control programmes the world-wide. Indeed, the large-scale production of Bti for mosquito control is very expensive due to the high cost of its culture. In the present study, we attempted to widen the scope in developing cost-effective culture medium for Bti production, based on the raw materials available on the biosphere, including coconut cake powder, CCP (Cocos nucifera), neem cake powder, NCP (Azadirachta indica) and groundnut cake powder, GCP (Arachis hypogea). Among these raw materials, the biomass production of Bti, sporulation and toxin synthesizing from 'CCP' in combination with mineral salt (MnCl(2)) was comfortably satisfactory. Bioassays with mosquito species (Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti) and field trials were also satisfactory. The present investigation suggests that coconut cake-based culture medium can be used as an alternative for industrial production of Bti in mosquito-control programme. Therefore, the study is very important from the point of effective production of Bti from cost-effective culture medium for the control of mosquito vectors.