In addition, emulsification test was carried out for the three organisms, and the results showed that Corynebacterium sp.
Emulsification test: The emulsification test for the cell free filtrate was carried out by growing the bacterial isolates in mineral salt medium supplemented with 0.10, 0.25, 0.50, 0.75 and 1.00% v/v of spent motor oil as sole carbon source and incubation for 24 h at 30 o C in a rotatory shaker at 200 rpm.
Emulsification test: The result of the emulsification test shows that Corynebacterium has the highest emulsification (77.40%) at 1% spent oil, while Bacillus has the highest emulsification (96.30%) at 0.25% spent oil, while the least is Pseudomonas, which is (40.0) at 0.25% spent oil (Table VI).