Heriot-Watt scientists crack oil-eating bacteria genetic code while testing oil spill water samples


Oil spill

Heriot-Watt scientists have discovered the genetic code of the marine bacteria which fed on the oil spilled in the Deepwater Horizon disaster, which could aid in future clean-up efforts.

In 2010, a gas release coupled with an explosion on the Deepwater Horizon oil rig working on the Macondo exploration well for BP in the Gulf of Mexico ejected 3.19 million barrels of oil into the ocean.

Heriot-Watt Microbiology associate professor Dr Tony Gutierrez experimented on samples of oil-contaminated waters from the Gulf of Mexico collected shortly after the incident, which contained the bacteria that fed on the oil.

“The incredibly diverse bacterial community that is ever present and living in the ocean stands at the ready, like an army of soldiers.”

The study has revealed that certain species of bacteria used the oil as their primary food source, whic subsequently helped with cleaning up the spill.

Dr Gutierrez, along with his colleagues from the University of Texas and the University of North Carolina at Chapel Hill discovered the genetic pathways used by the bacteria to feed on the oil, the conditions they thrive in, the kind of oil hydrocarbons they feed on, and the way they work during the oil spill.

Dr Gutierrez said: "Oil is a very complex fluid that contains thousands of different types of hydrocarbon chemicals, many of which are toxic and difficult to break down. But some of these bacteria can.

"Understanding which bacteria are important to breaking down oil could help lead to the design of emergency response plans that are more effective and environmentally friendly in combatting a major spill.

"We knew that certain bacteria will respond to and thrive during an oil spill and help break down oil, but we didn't know how this was coordinated."

The UK and US collaborative study has also revealed the ability of these bacteria to rapidly respond to oil discharged in water following a spill.

The team has also discovered bacteria that work at different depths, including Oceanospirillales feeding on alkanes in the deepwater oil plume, and Rhodospiralles and Cycloclasticus species that feed on polycyclic aromatic hydrocarbons (PAHs), which are considered to be some of the most toxic chemicals in oil.

Dr Gutierrez added: "Future oil spills are pretty much a certainty.

"This new information provides evidence that the incredibly diverse bacterial community that is ever present and living in the ocean stands at the ready, like an army of soldiers, to help degrade oil in the event of a spill.

"The hope is that our findings will allow us to exploit their oil-degrading potential on a wider scale, such as through more effective bioremediation strategies."


Image: Deepwater Horizon spill. Photo: courtesy of Andreas Taske, University of North Carolina Chapel Hill.