African Journal of Biotechnology Vol. 2 (9), pp. 288-292, September 2003

ISSN 1684-5315  © 2003 Academic Journals

Full Length Research Paper

Petroleum degrading potentials of single and mixed microbial cultures isolated from rivers and refinery effluent in Nigeria

P.O. OKERENTUGBA AND O.U. EZERONYE

Department of Microbiology University of Port Harcourt Choba, Port Harcourt, Nigeria.

*Corresponding author: E-mail: ezeronyeob@yahoo.com.

Accepted 29 July 2003

The ability of three bacterial isolates (Bacillus spp, Micrococcus spp and Proteus spp.) and some fungal species (Penicillin spp., Aspergillus spp. and Rhizopus spp.) isolated from two rivers and refinery effluent to degrade two Nigerian Crude oils was studied. The results showed changes in pH, optical density and total viable count for the bacterial isolates after a 17-day period. There was an increase in biomass for the fungal isolates after a 35-day period. It was observed that these organisms were able to utilize and degrade the crude oil constituents, with bacterial isolates showing increase in cell number and optical density as pH decreases. Single cultures were observed to be better crude oil degraders than the mixed cultures (bacteria or fungi). It was also observed that oil degraders could be isolated from a non-oil polluted environment, although those from oil-polluted environments have higher degradation potentials.

Key words:  Petroleum, refinery, biodegradation, plasmids, effluent.