The efficiency of Pseudomonas mendocina in biodegradation of chlorpyrifos insecticides

Abstract

At present, extensive varieties of pesticides are being used, but the demand for Organophosphorus pesticides is increasing globally to control insects. Chlorpyrifos is a broad-spectrum, highly toxic, and chlorinated organophosphate insecticide that is synthetic and usually an ester or thiol derivative of phosphoric. The mode of action involves inhibiting acetyl-cholinesterase, leading to the accumulation of acetylcholine, causing neurotoxicity. Bacteria capable of degrading the pesticide chlorpyrifos were isolated from soil contaminated with pesticides. This way, three distinct chlorpyrifos degrading strains of p.mendocina were isolated and characterized using morphological and biochemical analysis. Strains exhibited the greatest chlorpyrifos degradation rate, reaching 100%, and were consequently selected for further investigation. Degradation of chlorpyrifos by strains was rapid at 20 and 37C. Bacteria species were able to effectively degrade chlorpyrifos in a sterilized medium using high inoculum levels. The maximum degradation rate of chlorpyrifos was calculated as 100% during 6-12 days. Bacteria such as strain PC1 that use chlorpyrifos as a carbon source could be employed in biodegradation sites contaminated with pesticides. Keywords: Biodegradation; organophosphate; Chlorpyrifos; pseudomonas putida; Hplc.