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Mighty microbes might help clean up oil extraction and radioactive wastes

magnified e. coliThere appears to be literally nothing microbes cannot do. From the invention of photosynthesis to lifecycles that require no sunlight—even surviving extreme radiation—the most extreme microbes thrive almost everywhere scientists look. And now microbiologists have added two more energy-related tricks to the microbial arsenal.

At the European Society for General Microbiology meeting this week, Richard Johnson and his fellow scientists from the University of Essex will present research showing that a mixed ecosystem of particular bacteria can survive—and clean up—one of the most lethal man-made environments: the residue from extracting petroleum from oil sands.

Extracting this heavy oil and refining it produces a slew of toxic waste, particularly water with naphthenic acid (one of the secret ingredients of napalm). In Athabasca region of Canada—home to much of the oil sands industry—there are at least one billion cubic meters of such polluted water sitting in local ponds.

What to do? Unleash bacteria, Johnson says. The microbes can break down the naphthenic acid into more benign byproducts in a few days rather than the decade or more it can take naturally. This can cut down on the environmental impact of producing oil from tar sands, of which there is an estimated 3.6 trillion barrels (double known conventional oil reserves).

It does not, however, address that other related byproduct: climate change caused by the greenhouse gases emitted when the oil is burned. Maybe microbes can help with that too (after all, they were responsible for the composition of the atmosphere until humans came along).

And it turns out E. coli—most famous for its role in food poisoning—does a pretty good job of cleaning up another potentially important but lethal energy source: radioactive waste. Lynne Macaskie and colleagues at the University of Birmingham show in another presentation at the same meeting how said E. coli, in conjunction with a cheap, widely available chemical (inositol phosphate), can recover uranium from the polluted waters of mines.

Basically, the E. coli break down the chemical and free the phosphate, which then bonds with the uranium and forms a precipitate on the exterior of the cell that can be harvested.

The researchers estimate that such recovered uranium would cost about 15 cents per gram of the nuclear fuel element. But it also offers an environmental protection advantage, removing radioactive material from the mine tailings. The process could even be used on spent fuel rods and other nuclear waste.

Image: Courtesy of USDA Agricultural Research Service / Photo by Eric Erbe, digital colorization by Christopher Pooley

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