Biodegradation of chlorpyrifos by bacterial genus pseudomonas putida

Abstract

Chlorpyrifos is an solid organophosphorus pesticide widely used in agriculture. It is relatively stable to hydrolysis in neutral pH and acidic aqueous solutions. Stability decreases with increasing pH. Chlorpyrifos practically insoluble in water, but highly soluble in most organic solvents such as acetone xylene and methyl bromide. It is an effective skin, stomach and respiratory insecticide and is effective against aphids, spider mites, soil bugs and house pests. It is also highly toxic bees and fish. Most pesticides are complex organic molecules and are persistent in the environment, either biota or accumulate in the environment. In pesticide-used areas, the pesticide itself or its residues are transported by rain and irrigation water and mixes into groundwater. The effects caused by the pesticide are closely related to the level of accumulation. During the studies, contamination of chlorpyrifos has been found about 24 km from the site of its application. There are many physico-chemical and biological approaches to remove organophosphorus pesticides from the ecosystem, among them most promising is biodegradation. In this study, the biodegradation potential of chlorpyrifos with P. Putida was investigated in the batch stirred reactor. In the optimum conditions, the maximum pesticide removal rate was determined as 1.51 mg/g. d. m.o.h.