title: Degradation of polycyclic aromatic hydrocarbons in soil by a two-step sequential treatment.
abstract: The objectives of this work were to isolate the microorganisms responsible for a previously observed degradation of polycyclic aromatic hydrocarbons (PAH) in soil and to test a method for cleaning a PAH-contaminated soil. An efficient PAH degrader was isolated from an agricultural soil and designated as Mycobacterium LP1. In liquid culture, it degraded phenanthrene (58%), pyrene (24%), anthracene (21%) and benzo(a)pyrene (10%) present in mixture (initial concentration 50 microg ml(-1) each) and phenanthrene (92%) and pyrene (94%) as sole carbon sources after 14 days of incubation at 30 degrees C. In soil, Mycobacterium LP1 mineralised (14)C-phenanthrene (45%) and (14)C-pyrene (65%) after 10 days. The good ability of this Mycobacterium was combined with the benzo(a)pyrene oxidation effect obtained by 1% w/w rapeseed oil in a sequential treatment of a PAH-spiked soil (total PAH concentration 200 mg kg(-1)). The first step was incubation with the bacterium for 12 days and the second step was the addition of the rapeseed oil after this time and a further incubation of 22 days. Phenanthrene (99%), pyrene (95%) and anthracene (99%) were mainly degraded in the first 12 days and a total of 85% of benzo(a)pyrene was transformed during the whole process. The feasibility of the method is discussed.
authors.affiliation: Department of Microbiology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden. Leticia.Pizzul@mikrob.slu.se
authors.forename: Leticia
authors.initials: L
authors.lastname: Pizzul
authors.forename: Asa
authors.initials: A
authors.lastname: Sjögren
authors.forename: María Del Pilar
authors.initials: Mdel P
authors.lastname: Castillo
authors.forename: John
authors.initials: J
authors.lastname: Stenström
mesh_terms: D001564:Benzo(a)pyrene / Q000737:chemistry; D001673:Biodegradation, Environmental; D002244:Carbon / Q000737:chemistry; D052918:Environmental Restoration and Remediation; D005229:Fatty Acids, Monounsaturated; D006838:Hydrocarbons / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009161:Mycobacterium / Q000378:metabolism; D010938:Plant Oils / Q000378:metabolism; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D011083:Polycyclic Compounds / Q000737:chemistry; D011721:Pyrenes; D000074262:Rapeseed Oil; D012987:Soil; D012989:Soil Pollutants / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors
chemical_list: D005229:Fatty Acids, Monounsaturated; D006838:Hydrocarbons; D010938:Plant Oils; D011084:Polycyclic Aromatic Hydrocarbons; D011083:Polycyclic Compounds; D011721:Pyrenes; D000074262:Rapeseed Oil; D012987:Soil; D012989:Soil Pollutants; D001564:Benzo(a)pyrene; D002244:Carbon; C030984:pyrene