title: Ectomycorrhizas impede phytoremediation of polycyclic aromatic hydrocarbons (PAHs) both within and beyond the rhizosphere.
abstract: Exploitation of mycorrhizas to enhance phytoremediation of organic pollutants has received attention recently due to their positive effects on establishment of plants in polluted soils. Some evidence exist that ectomycorrhizas enhance the degradation of pollutants of low recalcitrance, while less easily degradable polyaromatic molecules have been degraded only by some of these fungi in vitro. Natural polyaromatic (humic) substances are degraded more slowly in soil where ectomycorrhizal fungi are present, thus phytoremediation of recalcitrant pollutants may not benefit from the presence of these fungi. Using a soil spiked with three polycyclic aromatic hydrocarbons (PAHs) and an industrially polluted soil (1 g kg(-1) of summation operator12 PAHs), we show that the ectomycorrhizal fungus Suillus bovinus, forming hydrophobic mycelium in soil that would easily enter into contact with hydrophobic pollutants, impedes rather than promotes PAH degradation. This result is likely to be a nutrient depletion effect caused by fungal scavenging of mineral nutrients.
authors.affiliation: Laboratoire des Interactions Microorganismes-Minéraux-Matière Organique dans les Sols (LIMOS), Université H. Poincaré Nancy 1, P.O. Box 239, F-54506 Vandoeuvre-les-Nancy, France. erik.joner@jordforsk.no
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Joner
authors.forename: Corinne
authors.initials: C
authors.lastname: Leyval
authors.forename: Jan V
authors.initials: JV
authors.lastname: Colpaert
mesh_terms: D001673:Biodegradation, Environmental; D017753:Ecosystem; D008903:Minerals; D038821:Mycorrhizae; D011084:Polycyclic Aromatic Hydrocarbons; D012988:Soil Microbiology; D012989:Soil Pollutants
chemical_list: D008903:Minerals; D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants