Mineralization and conversion of pentachlorophenol (PCP) in soil inoculated with the white-rot fungus Trametes versicolor

The fate of pentachlorophenol (PCP) in autoclaved soil supplemented with straw and inoculated with the white-rot fungus Trametes versicolor was investigated. Inoculated flasks were incubated for 0 to 42 d and control flasks for 0 to 28 d. Mineralization and volatilization of PCP and its transformation products were measured using 14C-labelled PCP for radiorespirometry and extraction analysis, and non-labelled PCP to monitor by use of gas chromatography transformation products of PCP. After incubation soil was extracted with water, dioxane, alkali (KOH–methanol) and the residue was combusted. PCP was analyzed from all extracts and its transformation products were analyzed from both water and dioxane fractions. During 42 d of incubation T. versicolor mineralized 29% of the PCP. The concentration of non-labelled PCP decreased to 4% of its original value during the incubation period. Only trace amounts of anisoles such as pentachloroanisole (PCA) and 2,3,4,6-tetrachloroanisole (2,3,4,6-TeCA) were formed during incubation. Part of the 14C-label was alkali-extractable, indicating that it was bound to humic substances, but this part was apparently later attacked and mineralized by the fungus. Results suggest that the treatment of PCP polluted soils with T. versicolor is a possibility.