BIOLOGICAL ELIMINATION OF POLYCYCLIC AROMATIC-HYDROCARBONS IN SOLVENTEXTRACTS OF POLLUTED SOIL BY THE WHITE-ROT FUNGUS, BJERKANDERA SP STRAIN BOS55

Polycyclic aromatic hydrocarbons (PAH) are persistent priority polluta nts of soil and sediments. Miscible solvent extraction of the soil has previously been shown to effectively clean-up PAH pollution. The purp ose of this study was to evaluate the use of the white rot fungus, Bje rkandera sp. strain BO555 in initiating the degradation of PAH present in solvent extracts. The PAH in extracts of polluted soil added to 9- day-old liquid fungal cultures were removed by 80% in 7 days with 2% ( v/v) ethanol in the medium. Smaller PAH compounds of only a few rings were degraded more rapidly than complexer FAH compounds having mole ri ngs. Phenanthrene, anthracene and pyrene with 3 to 4 rings were elimin ated by 96.8 to 99.5%; whereas, benzo[b]fluoranthene and indeno[123cd] pyrene of 5 and 6 rings were eliminated by 52 and 20% in 7 days, respe ctively. When the PAH extract of polluted soil was incubated in fungal cultures together with 20% acetone or ethanol, the cells were killed by the solvent. Nonetheless, partial bioconversion of PAH occurred whi ch was most likely due to the presence of extracellular peroxidases.