Degradation of petroleum hydrocarbons in two sub-antarctic soils: influence of an oleophilic fertilizer.
In order to determine the long-term effects of fertilizer on the degradation rate and the toxicity of hydrocarbons in sub-Antarctic soils contaminated by petroleum hydrocarbons, a field study was initiated in December 2000 on two different soils of the Kerguelen Islands (69 degrees 42'E, 49 degrees 19'S). The number of hydrocarbon-degrading bacteria (HDB) increased greatly after crude-oil and diesel-fuel contamination, and the fertilizer addition had a favorable effect on HDB growth and activity. Hydrocarbon-degrading bacteria counts remained high until the end of the experiment although the total hydrocarbon content in all contaminated soils was reduced to 80 to 90% of their initial value after 330 d. Degradation of n-alkanes was enhanced significantly in the presence of the fertilizer, while the degradation of polycyclic aromatic hydrocarbons (PAHs) was only barely enhanced. Toxicity results showed a noticeable reduction with time, although toxicity remained present and important in both soils at the end of the experiment. In addition, fertilized plots showed a toxic signal greater than unfertilized ones. Overall results clearly show that fertilizer addition improves the rate of degradation of both oil contaminants. However, remaining toxic residues may constitute a drawback of the fertilizer-assisted biodegradation process at low temperatures.
Coulon
Frédéric
F
Observatoire Océanologique de Banyuls, Université P. et M. Curie UMR-CNRS 7621, Laboratoire Arago 66650 Banyuls sur mer, France.
Pelletier
Emilien
E
St Louis
Richard
R
Gourhant
Lénaïck
L
Delille
Daniel
D
D000864:Antarctic Regions; D001419:Bacteria / Q000254:growth & development; D001673:Biodegradation, Environmental; D003080:Cold Temperature; D005308:Fertilizers; D006838:Hydrocarbons / Q000378:metabolism*; D010578:Petroleum; D011157:Population Dynamics; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*
D005308:Fertilizers; D006838:Hydrocarbons; D010578:Petroleum; D012989:Soil Pollutants