Role of a Paracoccus strain in the degradation and bioremediation of polycyclic aromatic hydrocarbons

Pouli, Maria [UCL] Fava, Fabio [University of Bologna] Agathos, Spiros N. [UCL]

Some bacterial strains were isolated after soil enrichments in the presence of chrysene as the sole carbon and energy source. The soil was collected from a petrochemical company site in Halong Bay, Vietnam. One of the chrysene enriched microbes was found to be a Paracoccus sp. In liquid cultures containing chrysene or pyrene as the sole energy and carbon source at the initial concentration of 200 mg l-1, this bacterium was able to degrade 80% and 77% respectively of the target compounds in 15 days. In order to test the efficiency of the Paracoccus strain in the bioremediation of soil polluted with polycyclic aromatic hydrocarbons (PAHs), experiments with soil slurry reactors were carried out on a well-characterized Italian pristine soil spiked with equal parts of phenanthrene, fluoranthene and pyrene to a final concentration of 2000 mg of total PAHs per kg of dry soil. The monitoring of the residual concentration of the PAHs demonstrated total removal of these contaminants over a period of 70 days.