Samples of used engine oil contaminated soil were collected from five different mechanic workshops in Sokoto metropolis to determine the presence of bacteria. Soil physicochemical parameters such as Carbon, nitrogen, phosphorus and others were determined. The bacteria identified include: Yersini ruckeri, Bacillus spp, Acinetobacter calcoaceticus, Lactobaccilus brevis, Staphylococcus spp, Pseudomonas aeruginosa, Proteus vulgar! s. Klebsiella ozanae and Flavobacterium odoratum. The isolates were cultured on oil medium to test their ability to grow on engine oil. The extent of used engine oil degradation was determined by gravimetric analysis. Flavobacterium odoratum (75.8%), Pseudomonas aeruginosa (74%), Acinetobacter calcoaceticus (73.7%) and Yersinia ruckeri (55.5%) were observed as the most efficient used engine oil degraders. The consortium of Flavobacterium odoratum, Acinetobacter calcoaceticus and Pseudomonas aeruginosa after three weeks show best result of engine oil degradation (81.8%). The results suggest that the consortium of the isolates could be used in remediating contaminated soils. Statistical analysis for total carbon, total nitrogen and rate of degradation of used engine oil by bacteria isolates procedure I and II showed significant difference between the samples and the rate of used engine oil degradation by the isolates.
