WASTEWATER TREATMENT SLUDGE AS A RAW MATERIAL FOR THE PRODUCTION OF BACILLUS THURINGIENSIS BASED BIOPESTICIDES

Wastewater sludge is a very good source of carbon, nitrogen, phosphorus and other nutrients. Seven wastewater sludges of different origins and types were used as an alternate culture medium for producing Bacillus thuringiensis variety kurstaki HD-1. Growth, sporulation and endotoxin production were affected by the sludge origin. Production performances were improved by sludge hydrolysis. As raw materials represent a substantial part of the overall Bt based biopesticide production cost, the use of wastewater sludge can be a new alternative for disposal/recycling and can substantially minimise the Bt production cost.