Biodegradation of pyrene during submerged cultivation of Trametes versicolor

Abstract

Pyrene is one of the most persistent pollutants belonging to the group of high molecular weight polycyclic aromatic hydrocarbons. Due to the presence of fused benzene rings these compounds are extremely difficult for biodegradation. The white-rot fungi possess remarkably high potential when it comes to the biodegradation of toxic organic substances with aromatic rings due to their unique lignin-degrading enzymatic complex. In the present study, pyrene with concentrations up to 200 ppm was added to the nutrient medium during submerged cultivation of the higher basidiomycete mushroom Trametes versicolor NBIMCC 8939. The experiment continued for 20 days and samples were taken every 5 days. Analysis of the activities of the enzymes laccase and manganese-dependent peroxidase were performed as well as determination of the residual pyrene concertation and identification of the by-products of the degradation process. It was established that the highest pyrene removal was achieved when the lowest initial concentration was introduced to the medium. The strain T. versicolor NBIMCC 8939 was able to biodegrade 12% of the initially introduced 50 ppm pyrene in the medium.