Evaluation of Different Culture Media for Improvement in Bioinsecticides Production by IndigenousBacillus thuringiensisand Their Application against Larvae ofAedes aegypti

Abstract

Production of indigenous isolateBacillus thuringiensissv2(Btsv2) was checked on conventional and nonconventional carbon and nitrogen sources in shake flasks. The effects on the production of biomass, toxin production, and spore formation capability of mosquito toxic strain were determined. Toxicity differs within the same strain depending on the growth medium.Btsv2produced with pigeon pea and soya bean flour were found highly effective withLC50<4 ppm against larvae ofAedes aegypti. These results were comparable with bacteria produced from Luria broth as a reference medium. Cost-effective analyses have revealed that production of biopesticide from test media is highly economical. The cost of production ofBtsv2with soya bean flour was significantly reduced by 23-fold. The use of nonconventional sources has yielded a new knowledge in this area as the process development aspects of biomass production have been neglected as an area of research. These studies are very important from the point of media optimization for economic production ofBacillus thuringiensisbased insecticides in mosquito control programmes.