In our fossil-fuel age, oil spills remain a major problem. From the Exxon Valdez to the recent Prestige disaster in Spain, several million tons of oil soils the world's seas every year, causing ecological catastrophe. Scientists developing cleanup strategies have looked to the microbes that thrive in the wake of such spills as one solution. Now, thanks to a detailed breakdown of one of the most effective of these oil-eaters, they are closer to having biologically based remedies for such environmental disasters.
Alcanivorax borkumensis is a rod-shaped bacteria that relies on oil to provide it with energy. Relatively rare in unpolluted seas it quickly comes to dominate the marine microbial ecosystem after an oil spill, and it can be found throughout the world's oceans. V¿tor A. P. Martins dos Santos of the German Research Center for Biotechnology and his colleagues broke the marine organism's genome into more than 3 million base pairs and then pieced them together into a complete genetic map.
That map contains several so-called islands that are unique to A. borkumensis, such as a set of genes that allow the organism to break down the alkanes in oil and use them as food. The microbe also has a wide variety of mechanisms by which it can take advantage of hydrocarbons, giving it a competitive advantage over similar organisms. Its dominance is also derived from its ability to use both organic and inorganic nitrogen: "although many constituents in crude oil are biodegradable, the main limitation to their actual biodegradation is nutrient availability, particularly nitrogen and phosphorous," the researchers explain in the paper presenting the genome in Nature Biotechnology.
By sequencing the genome of this oil-eating microbe, the scientists hope to harness its power to help clean up future oil spills. They write, "the genome data and their functional analysis provides us with an invaluable knowledge base essential to design, develop, test and optimize rational strategies to mitigate the ecological damage caused by oil spills in marine systems."