A microcosm system and an analytical protocol to assess PAH degradation and metabolite formation in soils.
During bioremediation of polycyclic aromatic hydrocarbon (PAH)-polluted soils accumulation of polar metabolites resulting from the biological activity may occur. Since these polar metabolites are potentially more toxic than the parental products, a better understanding of the processes involved in the production and fate of these oxidation products in soil is needed. In the present work we describe the design and set-up of a static soil microcosm system and an analytical methodology for detection of PAHs and their oxidation products in soils. When applied to a soil contaminated with phenanthrene, as a model PAH, and 1-hydroxy-2-naphthoic acid, diphenic acid, and phthalic acid as putative metabolites, the extraction and fractionation procedures resulted in recoveries of 93%, 89%, 100%, and 89%, respectively. The application of the standardized system to study the biodegradation of phenanthrene in an agricultural soil with and without inoculation of the high molecular weight PAH-degrading strain Mycobacterium sp. AP1, demonstrates its suitability for determining the environmental fate of PAHs in polluted soils and for evaluating the effect of bioremediative treatments. In inoculated microcosms 35% of the added phenanthrene was depleted, 19% being recovered as CO(2) and 3% as diphenic acid. The latter, together with other two unidentified metabolites, accumulated in soil.
Arias
Lida
L
Department of Microbiology, University of Barcelona, Diagonal 645, Barcelona 08028, Spain.
Bauzá
Jorge
J
Tobella
Joana
J
Vila
Joaquim
J
Grifoll
Magdalena
M
D007700:Kinetics; D009161:Mycobacterium / Q000378:metabolism*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000378:metabolism*; D012987:Soil / Q000032:analysis*
D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil