Background:
The invention employs a cost-effective high-yielding agro-based growth medium for the early, profuse sporulation and the process for the mass production of bio-insecticide, Bacillus thuringiensis. The millet-based agro-based medium is comprised of finger millet grain powder; defatted soybean, etc. This medium is supplemented with solid media with crop wastes to make it solid for mass production. The media is suitable for the efficient mass production of Bt spore-crystal toxin used for the management of insect pests:
Technology Details:
It discloses a process for the preparation of biocide using a cold-tolerant/environmentally competitive and highly entomopathogenic isolate (strain VLBt 6) of Bacillus thuringiensis subsp. galleriae/colmeri (MTCC 8997) isolated from the North-Western Himalaya. The strain is highly entomopathogenic and capable of producing a larger quantity of delta-endotoxin (crystal toxin) with a broad range as well as enhanced pesticidal/insecticidal activity. The strain is found highly insecticidal against diamondback moth Plutella xylostella, cabbage butterfly Pieris brassicae, cabbage semiloopers Thysanoplusiani and T. orichalcea, cabbage leaf webber Crocidolomia binotalis, amaranth leaf webber Hymenia recurvalis and tomato fruit borer Helicoverpa armigera, etc. The biocide is found quite toxic to the specific target insects but is harmless to plants and other non-targeted organisms. The solid and liquid media (VLBt S and VLBt L) and the production process are conveniently suitable for the efficient mass production of spore delta-endotoxin (crystal toxin) from many Bt strains at the village or farmer’s household level at small entrepreneurs’ level as well as at industries level using big fermenters and other downstream processing equipment. The process makes use of locally, abundantly available agro-industrial by-products thereby significantly reducing the overall cost of technology in addition to providing environmentally safe technology. The media of technology do not require the addition of many mineral salts for induction of sporulation. The external adjustment of media pH is also not required at any stage of the fermentation process. It also provides a composition of the formulation containing the biocide preferably delta endotoxin as an active ingredient and conventional acceptable carrier. The millet-based agrobased medium comprised of (a) 0.06 to 3.2 % by weight of finely ground finger millet grain powder; (b) 60 and 85% tap water; (c) 0.2 to 4.0 % by weight of finely ground defatted soybean; (d) 0.0 to 4.6% by weight of cow dung (e) 0.0 to 3.0 % by weight of cow milk and (f) 0.0 to 0.89 % by weight of sporulation enhancer selected from potassium di-hydrogen orthophosphate (KH2PO4). This medium is supplemented with solid media with crop wastes to make it solid for mass production.