Abstract
The biodegradability of a polycyclic aromatic hydrocarbons (PAHs) mixture consisted of fluorene (Fl), phenanthrene (Phe) and pyrene
(Pyr) by a bacterial consortium enriched from mangrove sediments under sediment-free and sediment slurry conditions was investigated. The
enriched consortium made up of three bacterial strains, namely Rhodococcus sp., Acinetobacter sp. and Pseudomonas sp., had a good PAH
degradation capability with 100% degradation of Fl and Phe in sediment-free liquid medium after 4 weeks of growth. The Fl and Phe
degradation percentages in sediment slurry were higher than that in liquid medium. Autochthonous microorganisms in sediments also
possessed satisfactory PAH degradation capability and all three PAHs were almost completely degraded after 4 weeks of growth.
Bioaugumentation (inoculation of the enriched consortium to sediments) showed a positive effect on PAH biodegradation after 1 week of
growth. Complete biodegradation of pyrene took longer time than that for Fl and Phe, indicating the enriched bacterial consortium had
preference to utilize low-molecular weight PAHs.
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