Degradation of Profenofos and λ-Cyhalothrin Using Endogenous Bacterial Isolates and Detection of the Responsible Genes

Abstract

An effective profenofos and λ-cyhalothrin degrading bacterium (strain DB17) was isolated from soil samples collected from Qassim region, Saudi Arabia. Based on the results of phylogenetic similarity of 16SrDNA gene sequences, strain DB17 was identified to be Pseudomonas putida. The isolate utilized profenofos and λ-cyhalothrin as the sole source of carbon for its growth. Analytical method was developed and validated for the determination of profenofos and λ-cyhalothrin in bacterial medium to monitor the intended biodegradation of both compounds. The inoculation of isolate DB17 109 and 1011 cells/ml to mineral salt medium supplemented by 100 mg/liter of profenofos and λ-cyhalothrin resulted in a higher degradation rate than in non-inoculated medium. The genes encoding organophosphorus hydrolase (mpd and opd) and pyrethroid-degrading esterase gene (pytY) were cloned using a PCR cloning strategy. The obtained results highlight the potential of this bacterium to be used in the cleanup of pesticide contaminated sites.