THE OXIDATION OF PYRENE AND BENZO[A]PYRENE BY NONBASIDIOMYCETE SOIL FUNGI

The purpose of this study was to determine the ability of nonbasidiomy cete soil fungi to oxidize pyrene (four rings) and benzo[a]pyrene (BaP ) (five rings). Fungi were isolated from five different soils in which the polycyclic aromatic hydrocarbon content ranged from 0.8 to 80 mu g/g dry soil. Approximately 50% of the isolates in all sites were able to oxidize pyrene. The pyrene-oxidizing species belonged to all funga l divisions except basidiomycetes. The most common were Penicillium sp p. of the subgenus Furcatum and these dominated the more contaminated soils. Penicillium janthinellum and Syncephalastrum racemosum exhibite d the most rapid rates of pyrene oxidation. The major pyrene metabolit es were identified by proton NMR and mass spectrometry as 1-pyrenol, 1 ,6- and 1,8-pyrenediol, and the 1,6- and 1,8-pyrenequinones. A high co rrelation was found between the ability to oxidize pyrene and BaP. As with pyrene, approximately 50% of the fungal isolates tested oxidized BaP to 9-hydroxy-BaP. Eighty percent of the pyrene-oxidizing strains w ere also able to metabolize BaP.