Microbial removal of polycyclic aromatic hydrocarbons by phanerochaete chrysosporium

Abstract

Inoculation of pure microbial culture to biodegrade recalcitrant organic compounds has had increased interest in the field of biological treatment of polluted waters or wastewater effluents. The removal of benzo(a)pyrene by the free cells of Phanerochaete chrysosporium strains, including ATCC 24725, ATCC 32639, and ATCC 34541, in a shaking vessel with a nitrogen-limited incubation medium was observed. This study also investigated the removal efficiencies of naphthalene, fluoranthene, and benzo(a)pyrene by immobilized white-rot fungus in a shaking flask and an aeration batch bioreactor. The biocarrier used in this investigation was a mixed gel composed of alginate and powdered activated carbon (PAC). The results showed that these polycyclic aromatic hydrocarbons (PAHs) were removed with an increased rate during the stationary growth phase, and strain ATCC 24725 exhibited the best PAH removal efficiency. No PAH residuals could be detected by HPLC from the immobilized-cell cultures in the shaking flask or aeration bioreactor during the incubation. However, a likely metabolite of PAH was identified in the chromatogram. The alginate-PAC biocarriers presented availability accessible pore volume for the colonization of fungus mycelia, moreover, the PAC fraction of the biocarrier obviously affected adsorptive capacities of PAHs.