WASTEWATER SLUDGE AS A RAW MATRIAL FOR THE PRODUCTION OF BIOPESTICIDES

Bacillus thuringiensis (Bt) is the only insect pathogens being commercially exploited extensively in different parts of the world. The commercial production of Bt for use as a biopesticide necessitates the search for cheaper locally available media ingredients. Several by-products of agro-industry, such as cotton seed meal, soybean meal, corn-steep liquor, cane sugar molasses are being employed for industrial production of Bt. Leguminous seeds such as horse gram, kidney bean, lima bean, soybean, chickpea, lentil, and peanut as the protein source for the growth of Bt var. kurstaki and var. entomocidus have been investigated. Use of groundnut cake and tamarind kernel powder as media ingredients for surface culture of Bt has also been reported (Noyamma et al., 1972). The use of groundnut cake aqueous extract, cow peas (white and black varieties), soybean and bambara bean along with cow blood powder for Bt var. israelensis growth in submerged fermentation has been reported by Obeta and Okafor (1984). Dehusked green gram powder and defatted soybean powder and either soluble starch or cane sugar molasses or both for δ-endotoxin production by Bt var. thuringiensis in submerged fermentation has been studied (Mummigatti and Raghunathan, 1990).