Biodegradation of anthracene and fluoranthene by fungi isolated from an experimental constructed wetland for wastewater treatment

Pilot-scale constructed wetlands were used to treat water contaminated by p olycyclic aromatic hydrocarbons (PAHs), particularly fluoranthene, and the possible role Of fungi Present ill these ecosystems was investigated. A tot al of 40 fungal species (24 genera) were isolated and identified from sampl es (gravel and sediments) from it contaminated wetland and a control wetlan d. All of them were assayed for their ability to remove anthracene (AC) and fluoranthene (FA) front liquid medium. FA was degraded efficiently by 33 s pecies while only 2 species were able to remove AC over 70%. A selection of 10 strains of micromycetes belonging to various taxonomic groups was furth er investigated for FA and AC degradation, toxicity assays and phenoloxidas es (POx) detection. Interesting and not previously reported species were re vealed (Absidia cylindrospora, Cladosporium sphaerospermum and Ulocladium c hartarum). They were all able to highly degrade the PAH-model compounds cho sen. Ali interesting inducibility wits noted for Ulocladium chartarum. Degr adative ability of fungi was not related to their extracellular POx activit y. This study may contribute to the improvement of constructed wetlands for water treatment, which may be enriched in efficient fungi. (C) 2001 Elsevi er Science Ltd. All rights reserved.