Bacillus aerophilus Mediated Degradation of Imidacloprid in Soil

Imidacloprid degradation potential of bacterial cultures isolated from sugarcane growing soils was studied in liquid culture and soil.Bacillus aerophilus showed maximum potential to degrade imidacloprid. Clay loam soil samples were fortified with imidacloprid @ 50, 100 and 150 mg kg⁻¹ along with 45x10⁷ microbe cells g⁻¹ in two opposing conditions viz., autoclaved and unautoclaved. To study degradation and metabolism of imidacloprid, samples were drawn at regular intervals of 7, 14, 28, 35, 42, 49 and 56 days. Three metabolites of imidacloprid viz. 6-chloronicotinic acid, nitrosimine and imidacloprid-NTG (nitroguanidine) were detected under both the conditions. Total imidacloprid residues did not follow the first order kinetics in both conditions. For the first time the use of pure cultures of soil isolated native bacterium B. aerophilus for remediation of imidacloprid contaminated soils is reported.