6.In vitro Assessment of Pseudomonas stutzeri
G. I. Ogu and Igborgbor J. C.
The assessment of Pseudomonas stutzeri’s biosurfactant on its hydrocarbon degradation potentials was studied in vitro. The reference chemical surfactant was Tween-80. Biosurfactant production was analyzed using emulsification index, oil displacement and drop collapse assay, while the petroleum hydrocarbon degradation potentials was determined in 2 % Escravos Light Crude Oil (ELCO)-amended mineral salt medium for 14 days using the standard gravimetric techniques. P. stutzeri’s biosurfactant gave a positive drop collapse test, with an oil displacement and emulsification stability index of 19 mm and 72.5% respectively. The petroleum hydrocarbon biodegradation analysis revealed that P. stutzeri respectively yielded 95.71% and 75.43 % in the presence and absence of 2% biosurfactant-amended medium after 14 days incubation. The results were statistically significant (P<0.05) when compared with the chemical surfactant which yielded 80.57 % biodegradation. Findings from this study suggest that P. stutzeri, isolated from crude oil polluted soil, possesses bioactive biosurfactant that might be exploited for enhanced bioremediation technology.