Waste Oil Biodegradation Potential among Bacteria Isolates from Waste Oil and Pristine Soils

摘要

The research study was aimed at investigating waste oil biodegradation potential among bacteria isolates from waste oil and pristine soil samples. Auto-mechanic workshop and pristine soil environments were randomly sampled within Calabar Metropolis. The study was completed within a period of six months. Standard microbiological methods were used to isolate, characterize and identify bacteria from the collected soil samples, while waste oil biodegradation potential of the bacteria isolates were determined using screen test for used engine oil and hydraulic oil utilization by bacteria isolates from both waste oil polluted and pristine soil. The level of turbidity, degree of precipitation and colour of precipitate were used to assess the biodegradation ability of the bacteria isolates. The total heterotrophic bacteria counts from the waste oil polluted soil samples ranged from 3.16x106 to 4.15x106cfu/g while that of the pristine soil sample ranged from 1.91x105 to 9.12x105cfu/g. Used engine oil biodegraders from the waste oil polluted soil were identified as Serratia spp, Enterobacter spp while efficient used engine oil and hydraulic oil biodegraders were identified as Shigella spp, Corynecbacterium spp, Klebsiella spp, Yersinia spp, Serratia spp and Aeromonas spp, Bacillus spp and Pseudomonas spp, while Serratia spp and Yersinia spp from the pristine soil also showed used engine oil biodegradation potentials and Bacillus spp was identified as efficient used engine and hydraulic oil biodegraders. However, it was obvious from the study that waste oil degraders and their proportion within an area appear to be marginally higher in environment with waste oil exposure and pollution as confirmed by the biodegradation potentials of bacteria isolates from the auto-mechanic workshop investigated, this therefore calls for the optimization of the process as it could serve as a more eco-friendly approach for the bioremediation of waste oil contaminated sites.