New studies are showing the effectiveness of tiny microbes on even the biggest cleanup jobs.Terry Hazen laughs when he is asked whether he’s ever surprised by the microbes he has studied for 30 years.
“I’m not,” he says. “I’m a firm believer in the doctrine of infallibility. What that means is there’s no compound known to man, man-made or natural, that bacteria can’t degrade.”
Hazen — an environmental microbiologist at the Lawrence Berkeley National Laboratory at the University of California, Berkeley— finds and feeds microbes that degrade pollutants into harmless elements, helping clean up some of the most polluted sites on the planet. The microbes, or “bugs,” as Hazen calls them, are everywhere — in the soil, the air and the oceans, where they naturally break down everything from methane to oil to the toxic byproducts of weapons-grade plutonium.
Hazen began his career researching the dark side of microbes, which, throughout history, have been the cause of plagues and ravages like the potato blight of the 1840s. But for more than two decades, he has discovered an increasing number of ways his bugs can help clean up environmental disasters and more effectively extract energy sources like oil and natural gas, all by simply doing what they’ve naturally evolved to do: break down compounds to their basic building blocks.
By the first week of August, roughly three months after the spill and three weeks after the well was capped, “we couldn’t detect anything. It didn’t surprise me at all. We’ve been working on oil spills for a very long time now,” Hazen says, though he makes clear that he doesn’t know how much oil may remain in sediment, where it biodegrades much more slowly.
Hazen says the type of spill, the Gulf of Mexico’s ecosystem and the consistency of the oil — which had been broken down into small droplets of light crude because of the pressure at depth and the use of dispersants — created perfect conditions for the microbes to do their work. The Gulf, he says, is home to numerous natural seeps of oil — more than 500,000 barrels annually, according to one study (unlike Prince William Sound in Alaska, the site of the Exxon Valdez spill, where oil-degrading microbes didn’t evolve because there were no natural seeps). When the Gulf spill occurred last April, analysis by Hazen’s team showed the number of bugs that degrade increased markedly. One microbe’s DNA constituted 5 percent of sequences analyzed outside the plume, but inside it made up more than 90 percent.
The work his team did in the Gulf may also make it easier to identify previously undetected spills and hold oil companies responsible for them, as the work on the Deepwater disaster shows the structure of a microbial community responding to a previous spill. “We may be able to use that as a technique to say even though we can’t see oil in situ or in a seep, there must have been oil leaked into that environment recently because we see the microbial community structure change,” he explains. “So we can use it as a forensic tool showing recent oil contamination.”