Abstract

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Biosurfactants from microorganisms are promising agents in the bioremediation of crude oil pollution due to their low toxicity and biodegradability. The study was aimed at screening bacteria isolated from petroleum contaminated soil for biosurfactant production. Soil samples were collected from 12 automobile workshops in Ago-Iwoye, Ogun State. Bacteria were isolated and characterized using pour plate technique and standard biochemical tests. Bacterial strains identified were screened for biosurfactant production using blood haemolysis test, drop collapse test, oil spreading test and foaming activity .accordingly. Of the forty five bacteria isolated and characterized. 60% were Gram-negative (27 strains) while (40%) were Gram-positive (18strains). Bacillus spp (24%) was the most dominant isolate followed by Pseudomonas aeruginosa (22%), Staphylococcus aureus (16%), Serratia marcescens (11%), Escheriachia coli (11%), Enterobacter aerogenes (9%) and Proteus mirabilis (7%) was the least. Results for biosurfactant screening showed that 69% of the isolates displayed haemolytic activity, 67% were positive for the drop collapse test, 75% were positive for the oil spread test and 36 % showed high foaming activities Pseudomonas aeruginosa and Bacillus spp showed high positive values in all the tests conducted. These organisms can be employed for future environmental friendly uses in bioremediation of oil contaminated environment.

Keywords: Biosurfactant, Oil contaminated soil, Automobile workshop