Screening for Biosurfactant Producing Bacteria from Petroleum Contaminated Soil of Automobile Workshops in Ago-Iwoye, Ogun State, Nigeria

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.",