Bioremediation Potentials and Emulsification Activity of Indigenous Bacteria Isolated from Crude Oil Polluted Soil in Ohaji-Egbema, Nigeria

Crude oil pollution is a global problem because of its hazardous effect to aquatic and terrestrial life, as well as having adverse effect on soil productivity. Bioremediation technology has been established as a successful alternative to physicochemical technique in cleaning up of contaminated site. This study was aimed at determining the bioremediation potentials and emulsification activity of indigenous bacteria isolated from crude oil polluted soil. Soil samples were randomly collected from Water-Smith and Base-Camp refineries in Ohaji-Egbema Local Government Area of Imo State, Nigeria. Bacteria isolation and identification were done using standard methods. The isolates were screened for crude oil biodegradation potential, and the extent of crude oil removal was determined using gravimetric method. Emulsification activity of the isolates was also determined using emulsification index (E24). Data were analyzed using analysis of variance (ANOVA) at P < 0.05. Bacteria isolates such as Arthrobacter sp., Enterobacter sp., Bacillus sp. and Pseudomonas sp. were identified in this study. Pseudomonas sp. achieved the highest extent of crude oil removal within the experimental period. Moreover, highest E24 of 81.80±2.8 and 84.00±4.0 was recorded in the media containing Bacillus sp. and Pseudomonas sp., respectively at 0.75mg/l crude oil concentration. Among the isolates, Pseudomonas sp. has greater potential for effective bioremediation of crude oil polluted soil as well as biosurfactant production due to its higher biodegradation efficiency and emulsification activity.