Scientists want to use bacteria to clean up oil spills - and

In 2010 the Deepwater Horizon oil spill released an estimated 4.2 million barrelsof oil into the Gulf of Mexico – the largest offshore spill in US history. The spill caused widespread damage to marine species, fisheries, and ecosystems stretching from tidal marshes to the deep ocean floor.

Emergency responders used multiple strategies to remove oil from the Gulf: they skimmed it from the water’s surface, burned it and used chemical dispersants to break it into small droplets.

However, experts struggled to account for what had happened to much of the oil. This was an important question, because it was unclear how much of the released oil would break down naturally within a short time.

If spilt oil persisted and sank to the ocean floor, scientists expected that it would cause more extensive harm to the environment.

Before the Deepwater Horizon spill, scientists had observed that marine bacteria were very efficient at removing oil from seawater. Therefore, many expertsargued that marine microbes would consume large quantities of oil from the BP spill and help the Gulf recover.

In a recent study, we used DNA analysis to confirm that certain kinds of marine bacteria efficiently broke down some of the major chemical components of oil from the spill. We also identified the major genetic pathways these bacteria used for this process, and other genes, which they likely need to thrive in the Gulf.

Altogether, our results suggest that some bacteria can not only tolerate but also break up oil, thereby helping in the cleanup process. By understanding how to support these natural occurring microbes, we may also be able to better manage the aftermath of oil spills.

Finding the oil-eaters

Observations in the Gulf appeared to confirm that microbes broke down a large fraction of the oil released from BP’s damaged well.

Before the spill, waters in the Gulf of Mexico contained a highly diverse range of bacteria from several different phyla, or large biological families. Immediately after the spill, these bacterial species became less diverse and one phylum increased substantially in numbers.

This indicated that many bacteria were sensitive to high doses of oil, but a few types were able to persist.