LAUSR

Abstract Bioremediation of pesticides is imperative for a sustainable environment. For this purpose soil borne, pure fungal strains; Aspergillus niger and Penicillium chrysogenum were augmented in soils spiked with herbicide, Chlorsulfuron from four distinct regions of Pakistan. These strains were found to utilize Chlorsulfuron as their carbon and energy sources. Solid-liquid extraction of pesticide was followed by analysis through high performance liquid chromatography and gas chromatography mass spectrometry. Chemical hydrolysis experiments, performed on the same soils were also found to degrade Chlorsulfuron (50%) but to a lesser extent than biodegradation (76 and 74% by both strains). Degradation rate followed first order reaction kinetics. Two major metabolites were obtained after degradation; 2-chlorobenzenesulfonamide and 2-amino-4-methoxy-6-methyl-1,3,5-triazine. Aspergillus niger degraded Chlorsulfuron (76%) slightly more than Penicillium chrysogenum (74%). R 2 for degradation rates for all soil samples by both fungal strains were close to 1 and P values were less than 0.05, indicating significance of results.