Bacillus thuringiensis bioinsecticide has been widely used on crops worldwide to replace chemical pesticides. B. thuringiensis production by solid-state fermentation requires less capital investment and modest technical skills. The method is often considered unsuitable for growth of aerobic organisms. However, optimization of Bt production using solid-state fermentation can effectively

contribute to promote use of this bacterium in insect pest management programs. Research into suitable nutrient concentrations of different media and characteristics of bacterial growth on these has enabled use of several agricultural or industrial by-products for mass production of several Bt strains. These materials include wheat bran, rice bran, rice crumb, and remaining barley from feeding of Sitotroga serealella. Wheat bran was the best of media for production of B. thuringiensis.