White-rot fungus Merulius tremellosus KUC9161 identified as an effective degrader of polycyclic aromatic hydrocarbons.

Polycyclic aromatic hydrocarbons (PAHs) have a highly recalcitrant structure; however, they can be degraded by white-rot fungi which have the potential to biodegrade recalcitrant organic compounds. Four fungal isolates were selected from 23 newly isolated basidiomycetes, based on their dye decolorization rate, and they were evaluated for their ability to degrade 50 ppm of pyrene. The isolate phylogenetically affiliated to Merulius tremellosus KUC9161 demonstrated the highest degradation rate of pyrene, regardless of the production of ligninolytic enzyme activities. The selected isolates were tested for their ability to degrade pyrene and other PAHs in creosote-contaminated soil. The results of the degradation tests indicated that M. tremellosus KUC9161 degraded a larger variety of PAH compounds than Phanerochaete chrysosporium, a known PAH degrader. On the basis of our results, the isolate M. tremellosus KUC9161 has a high potential to be used in the large-scale biodegradation of PAHs, and the species may also be used to degrade recalcitrant materials in creosote-contaminated soil.