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Studies on
the diversity, abundance and succession of hydrocarbon
utilizing micro organisms in tropical soil polluted with
oily sludge
Gerard Nkwelang1*, Henri F
L Kamga2, George E Nkeng 3,4 and S P
Antai5
1Faculty
of Science, Department of Biochemistry and Microbiology,
University of Buea, B.P. 63, Buea, Cameroon.
2Faculty
of Health Sciences, Department of Medical Laboratory
Sciences, University of Buea, BP 63 Buea, Cameroon.
3Faculty
of Science, Department of Chemistry, University of Buea, BP
63 Buea, Cameroon.
4ENSTP,
BP 510, Yaounde, Cameroon.
5Faculty
of Science, Department of Microbiology, University of
Calabar, P.M.B 1115, Calabar, Nigeria.
*Corresponding author. E-mail:
gerardnkwe@yahoo.com.
Tel: (237) 77844047
Accepted 29 February, 2008 |
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A research was carried out in a tropical region to study the
population of hydrocarbon utilizers in soil polluted with
oily sludge. Plots were prepared to receive treatments with
neat and emulsified oily sludge. These plots were further
treated with fertilizer and bioaugmented with a consortium
of hydrocarbon utilizers for six months. Results obtained
indicated that, the presence of oily sludge in soil caused
the growth of diverse genera of oil degraders. The major
genera of bacteria active in polluted soil were
Pseudomonas, Bacillus and Acinetobacter, while fungal
general were Aspergillus, Penicillium, and Mucor.
Abundant microbial growth was observed during the first 60
days. Some organisms such as Pseudomonas,
Bacillus, Penicillium, and Aspergillus were
present in polluted soil throughout the experimental period,
while others including Candida, Sporobolomyces
and Rhizopus were found only during the first two
months. Further analysis revealed that, succession of the
hydrocarbon utilizers in polluted soil was subject to
seasonal variations and depended primarily on the fraction
of the oil being utilized at a specific time and also on the
physiology of the micro organisms involved. In addition,
the selective appearance and succession of hydrocarbon
utilizers in the polluted soil were affected only by the
presence of neat and emulsified oil in soil as compare to
other treatment parameters. The practical implication of
these findings suggests that reloading of oil in some
treated plots could be carried out after the first 90 days.
Molecular techniques are underway to provide a more
comprehensive study on this successional trend.
Key words:
Microbial succession and diversity, oily sludge,
bioremediation, hydrocarbon utilizers. |
