keywords: Diesel, oil-degrading bacteria, Abattoir effluents
The microbial population and hydrocarbon utilizing microorganisms from Gwagwalada abattoir effluents within Abuja metropolis was investigated. This was carried out by the isolation of bacteria from abattoir effluents using the pour plate method. The heterotrophic bacteria isolated include Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. Hydrocarbon utilizing bacteria identified belong to the genera Pseudomonas, Bacillus, Escherichia, and Staphylococcus but Escherichia and Staphylococcus were the most occurring bacteria while Pseudomonas and Bacillus species were the least occurring bacteria. The residual diesel oil recovered in the mineral salt medium containing Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, and Staphylococcus aureus after 16 days of biodegradation was 0.03, 0.05, 0.08 and 0.08 ml per 10 ml of mineral salt medium, respectively from initial corresponding concentrations of 0.1 of diesel oil. The presence of bacteria which are indicators of faecal contamination as observed in this study are pointers to the dangers associated with the discharge of untreated abattoir wastes and effluent into the soil and water bodies. On the other hand, the abattoir effluent is rich in hydrocarbon utilizing microbes that can be harnessed for the clean-up of hydrocarbon contaminated soils.