Gopinathan Chengalath
Department of Biotechnology, University of Calicut, Kerala, India
Mosquito bites not only cause nuisance and discomfort but also transmit some of the very dreadful diseases such as Malaria, Dengue fever, Japanese encephalitis, etc. The massive uses of insecticides in the past few decades for the control of mosquitoes and other pests have resulted in environmental problems and health hazards. Bacillus thuringiensis israelensis, a rod shaped, gram positive, sporeforming bacterium has already been proven as a potent control for mosquito larvae. Bti is highly toxic to dipterans, at the same time safe to nontarget organisms and environment. Bti products contain spores and parasporal crystals of Bti H-14 serotype which must be ingested by the larval stage of the mosquito to cause mortality. Even though Bti products are efficient controls for mosquito and black fly larvae, their use in developing countries is limited by their cost. Thus, there is a need to reduce the overall production cost of Bti in order to make it competitive in the market. It depends on many factors; however, the raw material cost is one of the most important criteria, which may comprise >70% of the overall production cost. Local agro-industrial wastes when used as raw materials substantially reduces production cost.
The consumption of poultry meat grows year by year, which results in an increase of poultry waste production. The main waste are: feathers, skin, blood, heads and legs. Poultry processing plants currently convert feather waste into low-nutritive animal feed. Industrial methods of processing this waste are based on chemical (acid, base, catalyst) or enzymatic hydrolysis. Chemical hydrolysis requires more aggressive conditions of reaction (high temperature and pressure) and carries a greater risk to the environment. The product has a low nutritional value, and contains small amounts of the essential amino acids only. Poultry feather degradation using soil microbial consortia and using the resultant protein hydrolyasate containing amino acids for the growth and toxin production of Bti is the focus of this work. Effective degradation of poultry feathers by such soil microbial consortia can substantially simplify and reduce the conversion cost and ultimately the production cost of Bti.The potency of Bti samples produced using poutry feather hydrolyaste are assessed by performing biolarvicidal assay.