Bacteria isolated from various contaminated soils in
Nigeria were investigated for their potential to utilize and biodegrade
high molecular weight polycyclic aromatic hydrocarbons which include chrysene,
fluoranthene and pyrene. Biochemical and morphological studies identified
the isolates as Sphingomonas sp., Pseudomonas sp. and
Pseudomonas putida. Biodegradation studies showed that Sphingomonas
sp., Pseudomonas sp. and P. putida degraded 100 mg L-1
chrysene to 30.5±0.3, 40.6±0.7 and 17.2±0.2
mg L-1, respectively after 8 days of incubation. Similarly,
fluoranthene was degraded to 2.0±0.1, 2.0±0.4 and 0.12±0.1
mg L-1 while pyrene to 0.16±0.2, 6.5±0.3 and
6.6±0.4 mg L-1 correspondingly. Consortium of the isolates
degraded 100 mg L-1 chrysene, fluoranthene and pyrene, respectively
to 21.3±0.9, 2.2±0.8 and 10.6±0.8 mg L-1.
In the presence of phenanthrene as co-substrate, chrysene, fluoranthene
and pyrene were, respectively degraded by consortium to 12.4±0.5,
0.2±0.3 and 0.7±0.2 mg L-1 while phenanthrene
was undetectable. This study showed that there was delayed degradation
of chrysene and fluoranthene in the presence of phenanthrene, this may
account for the persistence of these compounds in polycyclic aromatic
hydrocarbons polluted sites. This is the first report on the potential
of these isolates simultaneous utilization and biodegradation of chrysene,
fluoranthene and pyrene when used as sole carbon and energy source.
M.N. Igwo-Ezikpe, O.G. Gbenle, M.O. Ilori, J. Okpuzor and A.A. Osuntoki, 2010. High Molecular Weight Polycyclic Aromatic Hydrocarbons Biodegradation by Bacteria Isolated from Contaminated Soils in Nigeria. Research Journal of Environmental Sciences, 4: 127-137.