Gulf Spill Reveals New Oil-Eating Bacteria

Researchers reporting in the journal Science say they have discovered a new species of oil-eating bacteria living half a mile down in the Gulf of Mexico. Study author Terry Hazen discusses the finding and what these bacteria might mean for future oil spills.

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IRA FLATOW, host:

It's been four months since the rig explosion that sent a gusher of millions and millions of barrels of crude oil into the Gulf of Mexico. And now that the well is capped, scientists are trying to answer the question on every mind -everyone's mind: How much oil was there and where did it all go?

My guest says he may have the answer. He and his team have been combing the Gulf waters, studying the fallout from the oil spill and writing in the journal Science. They report finding some very, very hungry microbes that like to just eat the oil and may have gobbled up much of it, which might answer the question where did the oil go.

And joining me now is Terry Hazen. He's a senior scientist and head of the ecology department at Lawrence Berkeley National Lab in Berkeley, California.

Welcome to SCIENCE FRIDAY.

Dr. TERRY HAZEN (Ecology Department, Lawrence Berkeley National Laboratory): Hi, Ira.

FLATOW: Hope I've got your name right.

HAEZN: You did.

FLATOW: Thank you. I'm always bad at that, as you know. Tell us about, say, your article - you - tell us about this new - these new bacteria, and they're not just one species, but a whole bunch of them that you've been finding out there.

Dr. HAZEN: Yeah. So what we did was to do some molecular techniques, looking at the RNA, DNA, proteins and lipids and show what the community structure was in this deep-sea plume that we saw, and then what - compare that to what we saw outside of that plume.

FLATOW: Mm-hmm. And what did you see inside that led you to find all of these different bacteria?

Dr. HAZEN: Well, the diversity went down, and basically, it's dominated by a fewer number of bacteria. You know, the species (unintelligible) went down. And we found that the bacteria that are there have genes that can degrade a variety of the hydrocarbons, and a lot of them are also cold-loving, in other words, they grow better at refrigerator temperatures than they do at room temperature.

FLATOW: And could they account for the missing oil?

Dr. HAZEN: They could account for some of it. Certainly, a lot of it could be diluting out. There's some strong currents down there too. But they're active down there. We've looked at couple of different techniques, brought them back to the lab and put fresh oil in there and got them - they basically degrade it in a fairly short period of time.

FLATOW: Talking about oil-eating bacteria in the Gulf of Mexico on SCIENCE FRIDAY from NPR. I'm Ira Flatow, talking with Terry Hazen.

And these bacteria live normally in the oil seepage that just pops up out of the ground, under the ocean there?

Dr. HAZEN: Yeah. You know, if I had to look for oil-degrading bacteria, and my colleagues, too, this would be one of the places that - especially in the deep sea - that we would look. There's the equivalent of two Exxon Valdez spills going into the Gulf every year from just natural seeps. And that's been going on for millions of years. So these bugs don't have much carbon down there, and what they do have is oil. And so, they've adapted to it.

FLATOW: And how good are they at it?

Dr. HAZEN: Pretty good. It looks like they can basically - we calculated this half-life, okay, so half of the oil being degraded in a certain period of time, and another half of the remaining being degraded, because there are some components that don't degrade as fast. But, you know, in as little as two or three days, we see half-lifes in that order.

FLATOW: Of the oil?

Dr. HAZEN: Yeah.

FLATOW: So if you had a barrel of oil and you stuck the bunch of these bacteria in it, within a few days, you'd have only half the amount?

Dr. HAZEN: Well, at that concentrations that probably wouldn't work. One of the, you know, particularly fortunate things in this deep-sea plume is it's highly dispersed in very low concentrations. And the oil from the MC252 Macondo well is light crude, a lot of volatile components. And so it's sort of inherently biodegradable, more so than the heavy crudes, like in the Exxon Valdez spill.

FLATOW: There's been press about your relationship with BP and a company that you work with is getting $500 million over 10 years from BP.

Dr. HAZEN: Well, it's not a company. It's University of California, Berkeley. And we had a program with the Energy Biosciences Institute, and we were doing the same sort of studies looking at these deep reservoirs. And I know if - on SCIENCE FRIDAY here about two years ago, we also had some discoveries that we made in South Africa, in some deep wells. We do that sort of thing normally. So it was just a natural thing for us to apply some of this research there and do this work down in the Gulf and try to help out and see if we could make some discoveries that might help.

FLATOW: So are you free to publish whatever your research findings are?

Dr. HAZEN: Absolutely. Anything I want to. And of course, I work for the - in the National Laboratory for the United States Department of Energy. And there's no restrictions on anything that we publish. In fact, BP has not even guided us or said - made even any - given us any ideas. We basically told them what we wanted and what we wanted to look at. And that's been it.

FLATOW: Could you tell at all what the effects of the dispersants, all those dispersants that were used on the oil, and do they have an effect on how effective the bacteria were?

Dr. HAZEN: Yeah. I think they did. We've got some studies that we're currently finishing with some of our collaborators at Penn State University in modeling, and it looks like the very small droplet size that were created by the dispersant in combination with the depth and this sort of thing, it's only 10 microns to 60 microns. And that gives a very good surface to volume ratio so that probably aided in the biodegradation, you know, at this depth.

FLATOW: Mm-hmm. I want to thank you, Terry, for taking time to be with us on SCIENCE FRIDAY today.

Dr. HAZEN: Happy to do it.

FLATOW: Good luck to you.

Dr. HAZEN: Thank you.

FLATOW: Terry Hazen is senior scientist and head of the Ecology Department at the Lawrence Berkeley National Lab, of course that's in Berkeley, California.

We're going to take a short break, change gears and come back, and talk about smell, the science of smell. What are you going to remember about the summer some of the summer's smells? Why does it invoke such great mysteries in your mind, and remembrances? So some of the science of smell coming back. Your questions, 1-800-989-8255. Stay with us. We'll be right back.

I'm Ira Flatow. This is SCIENCE FRIDAY from NPR.

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Deep In Gulf Water, Bacteria Are Eating Spilled Oil

There are some encouraging signs from the Gulf of Mexico that bacteria are consuming the underwater oil plume from the broken BP well. The news comes just days after oceanographer Christopher Reddy and a team from the Woods Hole Oceanographic Institution said they had found a big underwater oil plume in May and June, but no signs of oil-eating bacteria.

At the time, Reddy said microbes are about as predictable as teenagers.  "Microbes are pretty selective in how they eat oil," he explained.  "Sometimes they kick in; sometimes they don't. Sometimes they do the easiest work and they don't do the hard work."

The hard work is what scientists had been hoping to see — bacteria consuming the more toxic chemicals in the oil plume and rendering them harmless.  Reddy said sooner or later, the bugs should show up.

And now, apparently, they have.

"There's this unique cold-loving bacteria," says Terry Hazen, a microbiologist with the Lawrence Berkeley National Laboratory in California.  "They actually grow better at 5 degrees than they do at room temperature."

Hazen and a large team of scientists found these new, coldwater bacteria in the oil plume, 3,000 feet deep, and in the same plume the WHOI team was following.  There are several kinds of microbes, in fact — and they're eating the oil.

"Oil is the only carbon source down there deep, so they immediately take advantage of that," says Hazen.  "And of course they undoubtedly have been adapted to that over millions of years."

That's because oil has been in the water for millions of years, bubbling up from the seabed. "The Gulf has natural seeps that have been putting the equivalent of an Exxon Valdez spill into the Gulf every year," he says.

Every Spill Is Unique

So why hadn't other scientists seen the bacteria? One possibility is that they were looking for low oxygen levels in the water and didn't see that. Low oxygen is the principal sign that lots of bacteria are eating oil.

But Hazen says in this case, ocean currents and the use of dispersants has spread the oil out into a thin veil of tiny droplets.  So the bacteria are spread out too, and you don't find concentrated areas with low oxygen levels.

The reason Hazen's team found the bacteria is that they looked for genes and enzymes that the microbes express when they eat oil.

"The thing that I'm learning from this project is that there are no shortage of surprises from the microbial point of view," says Benjamin Van Mooy, a scientist with the WHOI team.

Van Mooy says every oil spill is unique "because the oil has a unique composition and it's also being released into an environment with its own unique chemical and physical factors at play.  And there's also the microbial community."

Scientists working on the Gulf spill say that's why it's hard to predict how the remaining oil in the Gulf will behave. Unlike the Exxon Valdez spill, the BP oil was released at the seafloor, under great pressure.  Dispersants spread it out into cold water, but as it rose, it reached much warmer water.

Hazen says it appears that the combination of bacteria and ocean mixing could degrade and disperse the remaining oil in a matter of weeks. "It does fit with what we've seen," he says. "So in the last three weeks, the plume at depth is completely undetectable."

But "gone" doesn't necessarily mean the Gulf is free of BP's oil.  Van Mooy points out that oil has scores of chemical constituents. Bacteria consume the "low hanging fruit" first, but the harder stuff takes longer to digest. And scientists who track oil say the plume may thin out in one place and then pop up in another.

The research, published in the journal Science, was funded by the federal Energy Department, along with support from BP through a university consortium.

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