Molecular Identification of Bacteria Involved in Degradation of Crude Oil

Abstract

In this present study, bacteria were isolated from soil obtained from oil contaminated
mechanic site in Enugu. Out of the 206 forming colonies, 16 colonies were selected based
on observable morphological differences and screened for crude oil degraders. Out of the
16 isolates, 11 isolates were assumed to be degraders because they formed maximum
clear zones on mineral salt media. At the end of 14 days incubation, 14 out of the 16
isolates degraded the crude oil ranging from 5% to 60%. Isolate 1, 5 and 14 had the
highest percentage degradation of 60%, followed by isolate 13 with 50% degradation.
Isolate 3 was the least degrader with 5% degradation while isolate 2 and 16 were not
able to degrade the crude oil. An attempt to identify the isolates was done by sequencing
the 16s rRNA gene of the isolates using DNA sequencing technique. Isolate 2, 3, 4, 5, 6,
and 7 were identified as Escherichia coli, Streptococcu anginosus strain SK52,
Lactobacillus spp. G12, Bacillus cereus strain ABc17, Paracoccus spp. KF89 and
Lactobacillus spp. G22 respectively. However, isolate 1, 8, 9, 10, 11, 12, 13, 14, 15 and 16 did not produce any result. This study shows that microorganisms isolated from a non
native crude oil contaminated site can be utilized for bioremediation.

Key words: Bioremediation, 16s rRNA gene, DNA sequencing, Biotechnology