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

Abstract

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.