The mineralization of [C-14]pyrene in sterilized and non-sterile soil
was investigated using the wood-decaying fungi Kuehneromyces mutabilis
and Agrocybe aegerita in a period of 63 days. In sterilized soil 5.1%
and 1.5% of the pyrene was mineralized to (CO2)-C-14 by K. mutabilis
and by A. aegerita, respectively. In non-sterile soil, 27.3% of pyrene
was mineralized by indigenous soil microflora including a Mycobacteri
um gilvum strain. During soil inoculation with fungi the mineralizatio
n was higher (47.7% for K. mutabilis and 38.5% for A. aegerita). For a
mass balance analysis the soil was extracted with toluene and methano
lic KOH (humic acid extraction). Considering the sum of mineralization
and formation of bound residues (nonextractable radioactivity), about
50% (sterilized soil) and 75% (non-sterile soil) of pyrene were elimi
nated by K. mutabilis. In comparison with indigenous soil microflora,
K. mutabilis enhanced pyrene elimination up to 42%.