Premium
Cometabolic mineralization of benzo[ a ]pyrene caused by hydrocarbon additions to soil
Author(s) -
Kanaly Robert A.,
Bartha Richard
Publication year - 1999
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620181010
Subject(s) - mineralization (soil science) , hydrocarbon , chemistry , environmental chemistry , pyrene , biodegradation , petroleum , organic chemistry , nitrogen
The mineralization of [7‐ 14 C]benzo[ a ]pyrene (B a P) in soil was investigated in response to additions of individual hydrocarbons, defined hydrocarbon mixtures, crude oil, and crude oil fractions. Neither substantial B a P mineralization nor enrichment of B a P degraders occurred in B a P—spiked soil in the absence of a suitable hydrocarbon supplement. Crude oil, the saturated and aromatic class components of crude oil, the distillates heating oil, jet fuel, and diesel fuel supported up to 60% mineralization of 80 μg [7‐ 14 C]B a P per gram of soil in 40 d. Neither single hydrocarbons nor defined hydrocarbon mixtures containing normal and branched alkanes, alicyclics, and aromatics supported comparable B a P mineralization. Evolution of 14 CO 2 occurred after lag periods characteristic to specific petroleum products and their concentrations. Time required for microbial proliferation, hydrocarbon toxicity, and competitive inhibition might have contributed to these lag periods, but the complete inhibition of B a P mineralization by dieselfuel vapors pointed to a dominant role of competitive inhibition. A lack of radiocarbon incorporation into soil biomass from [7‐ 14 C]B a P indicated that at least the initial steps of B a P biodegradation in soil were cometabolic in nature. Suitable hydrocarbon mixtures not only supported B a P mineralization by serving as primary substrates, but also enhanced B a P bioavailability by dissolving this hydrophobic solid.