The biotransformation of chrysene to trans-1,2-dihydroxy-1,2-dihydrochrysene by filamentous fungi

Abstract

The purpose of this study was to assess the ability of filamentous fungi isolated from petroleum-contaminated soils to oxidize chrysene. Only 4 of the 17 isolates known to oxidize pyrene and benzo[a]pyrene were found to produce polar products when incubated in the presence of chrysene and Tween 80: Penicillium janthinellum, Syncephalastrum racemosum, and 2 Penicillium spp. Trows-1,2-dihydroxy-1,2-dihydrochrysene was identified by 1H-NMR as one of three fungal metabolites. The extent of bioconversion to diol was approximately 3% of chrysene in 6 days. Experiments to increase chrysene oxidation with other polycyclic aromatic hydrocarbons were not successful. To our knowledge, this is the first identification of a chrysene metabolite from any microorganism and the first report of fungal oxidation of chrysene.Key words: chrysene, polycyclic aromatic hydrocarbons, filamentous fungi, bioremediation, cytochrome P450.