Abstract

The option of using microbes in the remediation of polluted sited have received wide acceptance due to its sustainability and environmental friendliness. This study is aimed at using the kinetic parameters (Vmax and Km) to assess the effect of organic and inorganic nitrogen sources on the performance of Pseudomonas sp., during the remediation of crude oil polluted sites. The rate of crude oil breakdown was assessed by determining the total petroleum hydrocarbon in the soil (after contaminating the soil with different percentages of crude oil) daily for 14 days. The experiment was repeated for different nitrogen sources (Azotobacter vinelandii, (NH4)2SO4, NaNO2 and NaNO3). The results of the experiments showed that the rate of breakdown of crude oil increases with increase in crude oil contamination in the different nitrogen sources except for the nitrate and the nitrite groups, where the rate reduced at 10% crude oil contamination. It was also observed that the introduction of various nitrogen sources decreased the Vmax and the Km. Pseudomonas sp., during the breakdown of crude oil showed a decrease in Vmax from 0.236±0.018-0.090±0.009, 0.137±0.005, 0.106±0.011 and 0.116±0.010 for the introduction of Azotobacter vinelandii, (NH4)2SO4, NaNO2 and NaNO3, respectively, 0.521±0.194. This shows that the introduction of the nitrogen source increase the affinity of the organism for crude oil.