African Journal of Biotechnology Vol. 2 (5), pp. 104-108, May 2003

ISSN 1684-5315  © 2003 Academic Journals

Biodegradation of Bonny light crude oil in soil microcosm by some bacterial strains isolated from crude oil flow stations saver pits in Nigeria

A. I. Okoh

Department of Microbiology, Obafemi Awolowo University, Ile – Ife, Nigeria. E-mail: aokoh98@hotmail.com; Tel: 234-803-7145687

Accepted 21 April 2003

In an effort at developing an active indigenous bacterial consortium that could be of relevance in bioremediation of petroleum contaminated systems in Nigeria, four hydrocarbon degrading bacteria strains were isolated. Partial sequencing of the 16S rDNA of the isolates suggests that they are all strains of Pseudomonas aeruginosa. Axenic cultures of the isolates biodegraded Bonny light crude oil in soil microcosm. Amount of crude oil biodegraded in 15 days ranged significantly (P < 0.05) from 4.9% to 29.6%. Degradation rates and specific growth rates varied significantly (P < 0.05) between 0.049 and 0.351 day^-1 and 0.017 and 0.028 hour^-1 respectively. Major peak components of the oil were reduced by between 6.5% and 70.6%. It would appear that oil degradation capability of axenic cultures of at least three of these isolates was not different from that of their consortium. Also, the multiple antibiotic resistance observed in the isolates is an important factor to consider in their eventual use in bioremediation exercises.

Key words: Crude oil, soil microcosm, biodegradation.