The in vitro-oxidation of the three-and four-ring polycyclic aromatic
hydrocarbons (PAH) anthracene, phenanthrene, pyrene and fluoranthene b
y preparations of extracellular lignin peroxidase (LiP), manganese per
oxidase (MnP) and laccase (Lacc) of the white rot fungus Nematoloma fr
owardii and by mushroom tyrosinase (Tyr) and horseradish peroxidase (H
RP) was investigated. LiP transformed 58.6% of anthracene and 34.2% of
pyrene, whereas 31.5% of anthracene and 11.2% pyrene were oxidized by
MnP. In the presence of the mediating substances veratryl alcohol (fo
r LiP), GSH (for MnP), and ABTS (for Lace, Tyr, HRP), the conversion o
f PAH was enhanced in most cases. Inclusion of PAM-derivatives, known
as intermediates or potential dead-end-products of microbial PAH metab
olism, in the in vitro-oxidation studies, demonstrated that the hydrox
ylated PAH metabolites served as substrates for all oxidoreductases te
sted, whereas PAH-quinones and ore-metabolites were not transformed.