It’s all about teamwork.
Cleanup after the largest accidental oil spill in history was a massive undertaking involving thousands of volunteers working over more than three years, and billions of dollars. All the while, microscopic communities of oil-eating bacteria that grew at exponential rates after the disaster were quietly contributing to the cleanup effort in their own way.
Scientists have now peered into the genomes of some of these bacteria to figure out how they were able to break down the oil, which consists of as many as 1,000 types of chemical compounds. Their findings were published in the journal Nature Microbiology.
The researchers pinpointed ways in which members of the diverse bacterial community worked together, combining their different capabilities, to consume the oil.
"It's equivalent to a concert," said Nina Dombrowski from the University of Texas Marine Science Institute and first author on the paper, in a press release. "All the musicians have to work together to make a piece of beautiful music. After the spill, all bacteria must work together to efficiently degrade oil."
Oil is complex, but contains two major compounds: alkanes, which are easy for bacteria to break down, and aromatic hydrocarbons, which can be highly toxic and challenging to break down. "We found a number of bacteria surprisingly capable of dealing with the more dangerous compounds,” said co-author Brett Baker, an assistant professor at the Marine Science Institute.
The DNA evidence even suggested that some bacteria can degrade the compounds found in dispersants, which were widely used after the spill to break oil into small droplets. Though their purpose is to facilitate biodegradation of oil by microbes, the dispersants themselves can cause environmental problems. However, as Dombrowski points out, not all bacteria respond well to dispersants so it is important to identify ones that are bacteria-friendly.
"Bacterial communities already present at the site of an oil spill can respond in a rapid and efficient manner, becoming abundant during the spill and actively degrading oil compounds," Dombrowski said. "This illustrates the importance of maintaining a healthy and diverse bacterial community, and why we need to be careful to make sure our response to a spill doesn't interfere with this natural response."