Tommy Phelps goes to extremes so we don't have to. A biologist with Oak Ridge National Laboratory, Phelps specializes in unearthing and studying 'extreme bacteria,' organisms that survive and thrive in remote and sometimes dangerous environments. The work has taken Phelps from national parks to miles-deep African mines. "You're always looking at the next frontier," Phelps said in an interview this month. "You see if there's a way you can add value to society."
Below are excerpts from our discussion.
What is "extreme bacteria" and why do you focus on it?
When people talk about bacteria from extreme environments, they're generally from environments that are atypical in one or more dimensions. It may be extremely high temperature. They may grow under high pressure. They're out of what we think of as our normal soil, water, microbial communities. These are organisms that have either evolved or adapted or survived in what we would consider very inhospitable environments.
They may have functions that are not only scientifically-interesting, but may be industrially-interesting. They might help us make new reactions, new products and new processes. Everyone talks about using molecular biology and DNA fingerprinting. There's an enzyme [Taq polymerase from the bacterium Thermus aquaticus] that came from Yellowstone National Park and is part of the polymerase chain reaction, which is used to make many copies of DNA segments for sequencing and genetic fingerprinting. You can argue that it has impacted everyone's life in this country and a decent percentage of lives around the planet.
Describe what you mean by 'inhospitable environments.'
The Hot Springs in Yellowstone are a perfect example. Yellowstone is visited by thousands of people a year, but most people are restricted to the drive and the boardwalks. Unknown to a lot of the normal population, there's a permitting process through the National Parks Service where you can get backwoods sampling permits. We can trek off from public view and sample the backwoods of Yellowstone. What most people see as a beautiful hot spring, we see as a source of interesting insights in biogeochemistry. Bacteria are growing in very hot waters or as hot water cools down. We looked at organisms that might be better at turning plants into fuels for our vehicles. If you go to spots that have bacteria at high temperatures, you look for bacteria that can degrade cellulose at high temperatures.
Talk about your experiences in the field.
We had an opportunity to work with great universities in South Africa. They had access to deep gold and metal mines. We went into mines sampling freshly blasted areas over a period of several years. We would get safety training. We went down in three-story elevators, known as cages. The first cage drop, around a mile or so, was a dead drop. When they would stop this descent, you would still bobble up and down a few times. That was the stretch of the steel cable after descending a mile. You'd walk to where you were sampling. At times, it was up to a three-mile walk. You might be riding on trains, walking beside train tracks and crawling in areas that had recently been mined.
When you go down in these places, you accept that you're not in control of your fate. You have people around you who are the only ones who know the way out. You're entrusting your life to them. [One trip] had taken a little longer than anyone thought. Suddenly, I heard a series of popping sounds. It was almost like a concussion wave. Then there was a plop, plop, plop of little pebbles dropping onto my hardhat. The first time, I just imagined it didn't happen. The second time, I asked what happened. [We had been scheduled] to take a cage to the surface an hour before. [But because the excursion had taken longer than expected], they'd already started the second shift. They're 100 meters above us blasting through rock and there's not a thing we can do about it. We've got a job to do. We finished our job and crawled several hundred feet and caught a later elevator to the surface.
That sounds grueling. Do you plan to continue this work long-term?
You can't do this indefinitely. We'd often go down these mines and be the oldest people there. You don't often see people in their 60s. You do have to watch it and slow down. At Yellowstone, I'll only go around the backwoods with younger people. As you get older, you have to be considerably more cautious and allow more margins for safety. You have to have a confident team. Some of my students have said that when I retire, they'd like me to go out with their students. Retiring may just be a change from being paid to do something versus volunteer work.
What's next for you and your work?
From the environmental side, we're focusing our efforts on climate change. We're doing more work with arctic permafrost and what would happen biogeochemically if permafrost starts to thaw. We're also going to start looking at the impacts of biogeochemistry in the Tropics if the climate starts heating or there are altered rain patterns. That's where we see the future projects that the Department of Energy will be interested in over the next several years.
On the bio-technology side, we are currently funded within a manufacturing demonstration facility. We're tasked with seeing if some of our organisms from these extreme environments can make nanomaterials of metals that would be appropriate and of use in industry. We're funded to scale up the processes. When people talk about making nanoparticles, often these processes are in terms of gram and milligram quantities. Can we make materials and hand industry a five-pound bag of it as a pilot product? We're working with several companies and expanding our portfolio of products that we can make using this bacteria.
Photo: Tommy Phelps looks for bacteria samples at Yellowstone National Park / Courtesy of Oak Ridge National Laboratory