Degradation mechanism and kinetics of carbendazim using Achromobacter sp. strain GB61

The present study was planned with the objective to isolate and characterize a carbendazim-degrading Achromobacter sp. strain GB61 from the contaminated agriculture field. Optimized carbendazim biodegradation (76.2%) by Achromobacter sp. strain GB61 was observed at 30 degrees C, pH 7.0, and 120 rpm within 20 days of incubation and was determined using response surface methodology. The degradation kinetics revealed the half-life (t(1/2)) of 7.3 days, and correlation coefficient (R-2) 0.0882 and degradation constant (K) 0.095 respectively. Maximum specific degradation rate (q(max)), half-saturation constant (K-s) and inhibition constant (K-i) were determined to be 0.122 d(-1), 0.724 mg L-1 and 271.71 mg L-1, respectively. Intermediate metabolites of carbendazim biodegradation confirming the formation of dihydroxybenzimidazole, 2-aminobenzimidazole and benzimidazole as intermediates. The results of the experiments suggested that the strain GB61 could be used for large-scale bioremediation of carbendazim contaminated environments.