Biodegradation of chlorpyrifos by charcoal–alginate immobilized bacterial consortium isolated from pesticide-polluted Kuzhikandam Creek, Kerala, India

Abstract

Chlorpyrifos, one of the most frequent organophosphorus pesticides, has been linked to major health problems and widespread environmental degradation. It is imperative to remove this herbicide from its point source of contamination since the risk of their off-site migration poses a health concern to non-target organisms. The objective of the present study was to investigate the biodegradation of chlorpyrifos 20% emulsifiable concentration (EC) utilizing a consortium of bacteria that had previously been isolated from a pesticide-contaminated site and are chlorpyrifos tolerant (S27I and S28I). Free cells and immobilized cells with chlorpyrifos as the only carbon source were used to analyze the biodegradation. Charcoal–alginate and kaolin–alginate were the immobilization matrices employed in the investigation. By using gas chromatography-mass spectrophotometer analysis, the degradation of chlorpyrifos was investigated. When compared to free cells, immobilized bacterial isolates showed the greatest amount of biodegradation in the investigation. Consortium (C1) among the isolates degraded chlorpyrifos most quickly compared to S27I and S28I. The study also examined the toxicity of chlorpyrifos at doses of 10, 25, 50, 75, and 100 ppm on the green gram seeds’ morphological parameters. Increased chlorpyrifos concentrations resulted in appreciable variations in the germination percentage, shoot length, and root length. The green gram germination study was used to evaluate the detoxification of chlorpyrifos following its breakdown.