Abstract

A. Sebiomo*, A. O. Awosanya and A. D. Awofodu

This study investigated the abilities of ten bacterial and five fungal isolates indigenous to polluted mechanic soils to utilise and degrade crude oil and gasoline. Of all the bacterial and fungal isolates obtained in this study Pseudomonas sp. Bacillus sp. and Aspergillus sp. were found to be more predominant in the polluted mechanic soils. The growth profiles were determined by monitoring the optical density, total viable counts, dry weights and pH of the culture utilizing crude oil and gasoline as carbon and energy source. Total viable counts increased significantly with optical density and dry weights of fungi as the days of incubation progressed until the 14th day (P<0.001). There was significant difference (P<0.002) in the pH values of the fungal isolates. The pH values decreased significantly (P<0.001) as fungal cells metabolised crude oil and gasoline. Of all the bacterial and fungal isolates used in this study Bacillus subtilis, Pseudomonas aeruginosa and Aspergillus ochraceus have shown the best abilities to utilise and degrade crude oil and gasoline in- vitro. All the organisms used in this study are all indigenous to the environment from which they were isolated and all of those which were tested for biodegradation were able to biodegrade organic contaminants actively. The biodegradation of contaminants is the best means to completely remove oil pollutants.