Bioremediation of endosulfan-contaminated soil by using bioaugmentation treatment of fungal inoculant Aspergillus niger

Th e persistence of endosulfan and intermediate metabolite endosulfan sulfate in the environment and their toxic eff ects on biota necessitate their removal. Th is study investigated the bioaugmentation of endosulfan-contaminated soil by fungal inoculant Aspergillus niger ARIFCC 1053. Th e infl uence of bioaugmentation by A. niger on endosulfancontaminated soil was evaluated with the help of change in pH and released chloride, and by thin layer chromatography and gas chromatography analysis. Its eff ects on soil functionality were monitored by estimating dehydrogenase and arylsulfatase enzyme activities. Th e endosulfan degradation reached an undetectable level on day 15. Th e pH of the medium was nearly neutral (6.9) at the time of inoculation and it decreased to 3.6 on day 15. Th e amount of chloride released at particular intervals in the endosulfan degradation ranged from 28 μg mL–1 to 104 μg mL–1. Change in pH and the increase in released chloride correlated with metabolic activities involved in the simultaneous degradation of endosulfan. Endosulfan sulfate, an intermediate metabolite, was detected and had disappeared on day 11 of the process. Th e increase in enzyme activities is an indicator of soil fertility and suggests possible involvement of these enzymes in endosulfan degradation. Th ese results demonstrate that bioaugmentation by A. niger may be a viable tool for the remediation of soil contaminated with endosulfan.