Biological Removal of Dibenzothiophene from Soil and Changes to soil Sulfate by White-Rot Fungus Phanerochaete chrysosporium

This study investigated biodegradation of dibenzothiophene (DBT) in marsh soil spiked bywhite-rot fungus Phanerochaete chrysosporium. Soil samples were spiked with 100 ppm DBT and incubated at 30°C in a dark chamber for 30 days. Samples were evaluated for pH, Mnperoxidase activity, sulfate ion concentration and growth during the tests. Results showed maximum levels of pH, Mn-peroxidase and sulfate concentrations at 8.19, 66 U L-1 and 31.21 mg kg-1 respectively. Colony forming unit assay determinations for contaminated soil samples showed that the fungus was able to grow and use dibenzothiophene as a source of carbon and energy. GC analysis of contaminated samples compared to control samples, demonstrated degradation of DBT by Phanerochaete chrysosporium. There was no significantly improved effect on degradation when the treatment was performed in presence of soil micro flora. The system attained a high rate of DBT degradation at approximately 83.34%, the 30 day test operation under optimal conditions. After 20 days, the sulfate ion concentration in soil samples had almost doubled.