title: Mycoremediation of wood and soil from an old sawmill area contaminated for decades.
abstract: We investigated the potential of white-rot and litter-decomposing fungi for the treatment of soil and wood from a sawmill area contaminated with aged chlorinated phenols, dibenzo-p-dioxins and furans (PCDD/F). Eight screening assays with emphasis on application of non-sterile conditions were carried out in order to select the strains with capability to withstand indigenous microbes and contamination. Nine fungi were then selected for degrading pentachlorophenol (PCP), and 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) and mineralizing radiolabelled pentachlorophenol ((14)C-PCP) in non-sterile soil or wood during 15 weeks of incubation. Soil indigenous microbes and fungal inoculated soil (fungal inoculum+indigenous microbes) achieved similar degradation of PCP and 2,3,4,6-TeCP and mineralization of (14)C-PCP. However, the mineralization rate of (14)C-PCP by indigenous microbes was much slower than that boosted by fungal inoculum. The litter-decomposing fungus (LDF) Stropharia rugosoannulata proved to be a suitable fungus for soil treatment. This fungus mineralized 26% of (14)C-PCP and degraded 43% of 2,3,4,6-TeCP and 73% of PCP. Furthermore, S. rugosoannulata attained 13% degradation of PCDD/F (expressed as WHO-Toxic Equivalent). In wood, white-rot fungi grew and degraded chlorophenols better than LDF. No efficient indigenous degraders were present in wood. Interestingly, production of toxic chlorinated organic metabolites (anisoles and veratroles) by LDF in wood was negligible.
authors.affiliation: Department of Food and Environmental Sciences, PO Box 56 (Biocenter 1), 00014 University of Helsinki, Finland.
authors.forename: Lara
authors.initials: L
authors.lastname: Valentín
authors.forename: Hanna
authors.initials: H
authors.lastname: Oesch-Kuisma
authors.forename: Kari T
authors.initials: KT
authors.lastname: Steffen
authors.forename: Mika A
authors.initials: MA
authors.lastname: Kähkönen
authors.forename: Annele
authors.initials: A
authors.lastname: Hatakka
authors.forename: Marja
authors.initials: M
authors.lastname: Tuomela
mesh_terms: D001487:Basidiomycota / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002713:Chlorine / Q000737:chemistry; D002733:Chlorophenols / Q000737:chemistry; D002849:Chromatography, Gas; D004875:Ergosterol / Q000737:chemistry; D007221:Industry; D010416:Pentachlorophenol / Q000737:chemistry; D012987:Soil; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry / Q000302:isolation & purification*; D013997:Time Factors; D014934:Wood / Q000737:chemistry* / Q000378:metabolism
chemical_list: D002733:Chlorophenols; D012987:Soil; D012989:Soil Pollutants; C031487:2,3,4,6-tetrachlorophenol; D002713:Chlorine; D010416:Pentachlorophenol; D004875:Ergosterol
keywords: Dioxin; Fungi; Furan; Pentachlorophenol; Stropharia rugosoannulata