Microbial degradation of second generation Neonicotinoid: Thiamethoxam in clay loam soils

Abstract

Thiamethoxam is a second-generation neonicotinoid poses risk to non-target organism and have potential of leaching to contaminate underground water. Biodegradtion of thiamethoxam by microbial species is a biological way to reduce the contaminant. In the present paper, persistence of thiamethoxam in clay loam soil was studied for 56 days in laboratory conditions. Bacillus aerophilus strain IMBL 4.1 bacterium isolated from field soil and used to spike the soil sample containing different concentration (25, 50 and 100 mg kg−1) of thiamethoxam. Bacillus aerophilus strain IMBL 4.1 resulted in the active biodegradation of thiamethoxam. Half-life (t1/2) and the correlation coefficient (R2) were studied and none of value was found more than 0.99 (R2 values) so, total thiamethoxam residues did not follow the first-order kinetics neither in control nor in amended samples. From the study, it was demonstrated that B. aerophilus has potential for biodegradation of thiamethoxam in clay loam soils.