Petroleum bioremediation is carried out by microorganisms capable of utilizing hydrocarbons as a source of energy and carbon [7,8,9•].
These microorganisms are ubiquitous in nature and are capable of degrading the various types of hydrocarbons — short-chain, long-chain and numerous aromatic compounds, including polycyclic aromatic hydrocarbons.
All these compounds have low solubility in water.
This fact, coupled to the fact that the first step in hydrocarbon degradation involves a membrane-bound oxygenase, makes it essential for bacteria to come in direct contact with the hydrocarbon substrates.
One biological strategy that can enhance contact between bacteria and water-insoluble hydrocarbons is emulsification of the hydrocarbon.
Therefore, it is not surprising that bacteria growing on petroleum usually produce potent emulsifiers.
These surfactants help to disperse the oil, increase the surface area for growth, and help detach the bacteria from
the oil droplets after the utilizable hydrocarbon has been depleted