Investigation on the hydrocarbon utilization potential of Pseudomonas putrefaciens, Bacillus stearothermophilus and Streptococcus faecium isolated from crude oil contaminated soil

The biodegradation potential of Pseudomonas putrefaciens, Bacillus stearothermophilus and Streptococcus faecium isolated from crude oil contaminated soil was investigated in this study. The 3 bacteria strains were inoculated into crude oil supplemented with Mineral Salt Medium and incubated at 37 °C for 25 days. The results obtained showed that P. putrefaciens, B. stearothermophilus and S. faecium were able to degrade 70%, 58% and 48% at the end of 25 days of incubation respectively. IR analysis of the residual crude oil was done, the results obtained showed that the bacteria strains have exerted microbial action on the crude oil. The results obtained from IR analysis revealed 17 bands, 16 bands and 12 bands for P. putrefaciens, B. stearothermophilus and S. faecium respectively, while control had 10 bands. This is an indication that the bacteria strains have modified the crude oil constituents. P. putrefaciens had highest percentage of degradation compare to the other two bacteria. The order of degradation was as follows P. putrefaciens > B. stearothermophilus > S. faecium. This study showed that the bacteria strains used in this study could be relevant in the bioremediation of ecosystem that may be contaminated with hydrocarbons