Biodegradation of petroleum hydrocarbons as a
decontamination mechanism is a relatively slow process.
This study aimed to investigate the impact of a tailored
consortium of bacteria with higher capacities in biosurfactant
production and biodegradation on the acceleration
of the biodecontamination process. To this end, 18 biosurfactant
producing bacteria were isolated from the crude
oil-contaminated soil samples of Isfahan refinery, and the
activity of the produced biosurfactants was measured in
terms of surface tension reduction and emulsification E24
test. Then, the isolates screened for the biodegradation of
kerosene hydrocarbons and chemical structure of the
purified biosurfactants produced by the most efficient isolates
were partially characterized. Next, the isolates were
sorted based on their surfactant activity and biodegradation
efficiency, and the higher ranked bacteria thus selected
were utilized to form an efficient consortium removing
hydrocarbons from the oil-contaminated soil samples in a
slurry phase system. The consortium consisted of
Bacillus subtilis
tb1 and
Pseudomonas aeruginosa
species having
the highest biodegradation capabilities and surface activities.
The results revealed that the hydrocarbon removal
efficiency of the consortium was at least 25 % higher than
single species, and the final removal efficiency for the
consortium could be reached in a considerably shorter time.
