Biodegradation of Cypermethrin by a Pseudomonas Strain Cyp19 and its use in Bioremediation of contaminated soil

Abstract

Pyrethoids are commonly used insecticide in both agricultural and urban environments. In this paper we describe isolation of a bacterium capable of degrading cypermethrin. The bacterium was isolated from a pesticide contaminated soil by enrichment technique with continuous pressure of cypermethrin as the sole carbon source and energy. Morphological, physiological and biochemical characterization of the bacterium indicated that it was a Pseudomonas species. The degradation ability of the isolate determined by resting cells study revealed that strainCyp19degrades cypermethrin upto 100% within two days. Degradation of cypermethrin in unautoclaved inoculated and autoclaved inoculated soil was 97.5% and 95% respectively after 30-days of incubation studies, whereas it was insignificant in unautoclaved (uninoculated) and autoclaved (uninoculated) soil. The addition of strain Cyp19 (10 cells g) to soil with a low indigenous population of cypermethrin degrading bacteria treated with 40 ppm of cypermethrin g resulted in a higher degradation rate than was observed in noninoculated soils. These results highlight the potential of this bacterium to be used in cleanup of contaminated pesticide waste in the environment.