Cypermethrin Degradation Using Klebsiella Pneumoniae and Checking Toxicity of Degradation Products on Aquatic Life

Agricultural loss due to different pests is increasing extensively. Various chemical pesticides like organophosphorus pesticides, organochlorines, carbamates are being used for control of the various pests. But these pesticides are found to be associated with different side effects and toxicity to human beings and to aquatic life. So, these pesticides have been banned for use by many countries. Therefore, synthetic pyrethroids are being used extensively in the agriculture after the ban over organochlorine and organophosphorous pesticides. Cypermethrin is the fourth generation pyrethroid useful against pests of fruits, vegetables and household insects. Cypermethrin shows affectivity against different pests at low concentration but at the same time shows toxicity to human beings and to aquatic life. So, removal of these pesticides from soil is very important for crop protection. Focus of this paper is degradation of cypermethrin by using rhizospheric isolates. For this, different isolates were obtained from soil samples and checked for their capacity of cypermethrin degradation. Two isolates showing capacity of cypermethrin degradation were identified by 16S rRNA. One of the isolate K. pneumoniae was used for cypermethrin degradation. Cypermethrin degradation was confirmed by detecting reduction in the COD values. COD value was found to reduced more than 50%. Cypermethrin degradation metabolites were detected by GC-MS analysis and different degradation metabolites were identified by comparing with standard database. Toxicity of the cypermethrin degradation product was tested by fish bioassy. It was found that guppy fishes could survive up to 48 hrs in presence of cypermethrin degradation product whereas in control fishes were died within half hour.