The Deepwater Horizon oil spill in the Gulf of Mexico occurred in 2010 and it has been widely studied. One factor that is yet to be resolved is what happened to the oil slick and how did it disappear? (in all 1 million barrels of crude oil were released into the ocean). Microorganisms certainly played a role, but there has not been clear agreement between microbiologists as to the precise role played by marine microbes and how they succeeded in degrading the oil. A new study promises a new insight.
The study comes from the U.S. Department of the Environment and the Lawrence Berkeley National Laboratory. Work performed by Ping Hu and Gary Andersen suggests a complex community microbes that specialize as hydrocarbon-degraders. This was shown by performing a simulation whereby the science team replicate a mini-version of the oil spill in a laboratory. This was to understand the mechanisms for oil degradation from each of the primary oil-degrading bacteria identified from samples taken during the time of the 2010 disaster.
The research model was made up of a suspension of small, insoluble oil droplets together with more soluble oil fractions and the chemical dispersant used to help clear the oil at the time. Each of these elements helped to mimic the conditions of the 2010 oil plume. What was important for the study was using bacteria collected from the original disaster site. The Gulf of Mexico is host to the largest concentrations of underwater hydrocarbon seeps together with a rich diversity of oil-degrading microbs.
This analysis showed that one bacterium was especially dominant and accounted for the greatest degradation of the oil. This was discovered via DNA sequencing, leading to the organism being named Bermanella macondoprimitus. This organism possesses specific genes that allow for oil degradation.
Understanding more about this organism means that it could be possible to develop a biological response using live organisms for a future oil disaster. At present the bacterium is difficult to move from its natural ecosystem to a different part of the ocean or even to cultivate in the laboratory. This is being examined, with a view of creating an bio-response to future oil slicks.
The research paper, published in Proceedings of the National Academy of Sciences, is titled “Simulation of Deepwater Horizon oil plume reveals substrate specialization within a complex community of hydrocarbon-degraders.”
