Biodegradation of organophosphorus insecticides,chlorpyrifos,by pseudomonas putida CP-1

Synthetic organophosphorous pesticides (ops) are highly toxic compounds used widely,amounting to about 38% of the world-wide pesticides. the enormous and inadequate use of ops is a continuous threat for the whole ecosystem due to their persistence and toxicity. this study was designed to isolate chlorpyrifos degrading bacteria from indigenous soil. after successive enrichment process and sub-culturing on phosphate free medium,a single bacterial strain has been isolated from contaminated soil,designated as cp-1. the strain cp-1 was identified on the basis of sequence homology of 16s rrna gene and found to be pseudomonas putida. it can grow efficiently on phosphorus free media while utilizing chlorpyrifos as a sole source of phosphorus. this ability indicates that the bacterium has phosphotriesterase that hydrolyzes the phosphotriester bond of chlorpyrifos. cell free extract (cfe) obtained from p. putida cp-1 further confirmed the triesterase activity as it hydrolyzes chlorpyrifos and gives 3,5,6-trichloro-2-pyridinol (tcp) as a major metabolite. © copyright 2016 zoological society of pakistan.