Petroleum-eating bacteria can clean up oil spills

From pipelines to tankers, oil spills and their impact on the environment are a source of concern.

These disasters occur on a regular basis, leading to messy decontamination challenges that require massive investments of time and resources.

Professor Satinder Kaur Brar and her team at National Institute of Scientific Research (INRS) in Canada have conducted laboratory tests to show the effectiveness of Alcanivorax borkumensis - a bacterium that feeds on hydrocarbons.

The results offer hope for a simple, effective, and eco-friendly method of decontaminating water and soil at oil sites.

In recent years, researchers have sequenced the genomes of thousands of bacteria from various sources.

Research associate Tarek Rouissi poured over "technical data sheets" for many bacterial strains with the aim of finding the perfect candidate for cleaning up oil spills.

He focused on the enzymes they produce and the conditions in which they evolve.

The genome of A borkumensis, a non-pathogenic marine bacterium, contains the codes of a number of interesting enzymes and it is classified as "hydrocarbonoclastic" - that is, a bacterium that uses hydrocarbons as a source of energy.

A borkumensis is present in all oceans and drifts with the current, multiplying rapidly in areas where the concentration of oil compounds is high, which partly explains the natural degradation observed after some spills. However, its remedial potential had not been assessed. During its evolution, A borkumensis accumulated a range of very specific enzymes that degrade almost everything found in oil.

Among these enzymes, the bacteria's hydroxylases stand out from the ones found in other species. They are far more effective, in addition to being more versatile and resistant to chemical conditions, as tested in coordination by a PhD student Tayssir Kadri. To test the microscopic cleaner, researchers purified a few of the enzymes and used them to treat samples of contaminated soil.

"The degradation of hydrocarbons using the crude enzyme extract is really encouraging and reached over 80% for various compounds," said Brar.

"The process is effective in removing benzene, toluene, and xylene, and has been tested under a number of different conditions to show that it is a powerful way to clean up polluted land and marine environments," she said.

Researchers found out more about how these bacteria metabolise hydrocarbons and explore their potential for decontaminating sites.

One of the advantages of the approach developed at INRS is its application in difficult-to-access environments, which present a major challenge during oil spill cleanup efforts.