The Evaluation of Imidacloprid Remediation in Soil Media by Two Bacterial Strains

Imidacloprid (C₉H₁₀ClN₅O₂) is used as the most recommended type of insecticide in vegetable farming worldwide. Two types of bacteria (Methylobacterium radiotolerans and Microbacterium arthrosphaerae) were isolated from a corn farming field in the Thrace region of Turkey, and then consortia of these bacteria were prepared from equal volumes of 10⁷ CFU/ml for each bacterium type. Imidacloprid remediation studies were carried out during 18 days in soil test units. The water filtered from these soil test units was determined for chemical oxygen demand (COD) and biochemical oxygen demand (BOD₅) to determine the optimum concentration of microorganisms to ascertain the best removal efficiency of Imidacloprid. COD removal rates were 98.7%, 96.4% and 51.6% with 80, 40, and 20 ml volumes of the consortia of bacteria, respectively, at the end of 18 days. The BOD₅ removal rates were 88.4%, 78.6% and 49.9% in the same volumes of bacteria, respectively. As a result of this study, we have found that this bacterial consortium is very effective for the bioremediation of this insecticide at the two volumes of 40 and 80 ml, both being better than 20 ml.