Petroleum degrading potentials of Bacillus sp isolated from an oil-contaminated soil was determined in the laboratory through growth in 5% Automated Gas Oil-supplemented minimum basal media at room temperature (30 ± 20C). Pure cultures of Bacillus sp were then subjected to mutation using 0.01%, 0.1%, 1% and 10% nitrous acid and by exposure to X-rays for 2 and 5
seconds and their petroleum degrading potentials were determined for 7 days. It was observed that both the parent and mutants degraded petroleum with the nitrous acid mutants possessing varying increased potential than the parent stock. F-tests at 95% confidence level showed
significant differences in total aerobic counts and pH. There were no significant differences in temperature between parent and mutants in both treatments. Thus, while both nitrous acid and Xrays could initiate mutation in Bacillus sp, only the nitrous acid mutants possessed the desirable greater potentials to degrade the petroleum product and could thus be employed in the bioremediation of petroleum or its products.