|by Annette Trinity-Stevens
Wanted: Algae of the most adventurous type. Must grow in slime on scratchy plastic discs.
A willingness to be periodically purged in favor of new recruits required. Above all, must have
a hearty appetite for carbon dioxide and a tolerance for scalding temperatures.
This is roughly the job description Keith Cooksey, professor or microbiology at Montana State
University-Bozeman, carries with him as he searches the hot springs of Yellowstone National Park
Cooksey's on a mission, of sorts. Well, a subcontract, really. He's part of a three member team
looking for ways of naturally lowering carbon dioxide emissions from coal-fired power plants.
Besides Cooksey, the threesome includes David Bayless, a mechanical engineer at Ohio University,
and researchers from Oak Ridge National Laboratory in Tennessee. Helping Cooksey at MSU is
postdoctoral researcher Igor Brown.
Together, the group has $1 million from the U.S. Dept. of Energy. Cooksey and Brown's portion of
the project is about $100,000 a year for three years. Brown also has support from the MSU
Thermal Biology Institute, which similarly studies unique microbes from Yellowstone.
While the coal-fueled power industry has reduced particulate and sulfur emissions, it still
produces high amounts of carbon dioxide and other greenhouse gases, now believed to be
undesirably warming the planet.
Ohio University is experimenting with ways of absorbing carbon dioxide with algae. Like other
plants, algae use the gas as part of their metabolic process called photosynthesis.
Ohio University has piloted Bayless's technology using algae from the desert. But they believe
there's a better organism out there, and now it's Cooksey's job to look.
"If you ant thermotolerant, we're in a good place to look," Cooksey says, referring to Yellowstone
National Park. The park is well known for heat-loving organisms that live in and around park hot
"They must be thermotolerant because the gases from these coal-fired power plants -- which are
about 14 percent carbon dioxide -- are hot," Cooksey said. "The gases have been through the
scrubbers to get rid of the ash, but they still have lots of CO2."
Is it likely he'll find what he's looking for?
"I'm sure it is," he said without hesitation.
"I suspect Keith is right," echoed Ann Deutch, research permit coordinator for the park. "I have no
reason to believe he won't succeed."
After all, fewer than one percent of the park's microorganisms have been discovered and characterized,
Deutch said, meaning so many more algae and related organisms are yet to be found. As microbiologists
continue to improve their ability to look, they find greater layers of complexity in the microbial
community, she said.
When Cooksey finds some likely candidates, he'll isolate them and describe them on plastic sanding
discs in a layer of slime called biofilm. Oak Ridge National Labs has figured out how to pipe
sunlight to the algae from roof-top solar collectors. Power-plant gases would first be scrubbed of
their flyash and sulfur, then piped through mats of algae before going out the smokestack, Cooksey
"That exhaust is what we're going to remove the CO2 from," he said. "We don't know how much CO2 we
can get out of it."
Cooksey also doesn't yet know how long the algae can do their job before having to be regrown.
Harvested algae would likely be used as fertilizer, since they would be rich in both carbon and
Elsewhere, scientists are contemplating other ways of absorbing excess carbon dioxide. One approach,
which Cooksey finds troubling, is injecting it into oceans. He'd rather hire a microbe from
Yellowstone, born and breed to handle heat, for the hot-gas industrial assignment.
Deutch, too, likes the idea of a Yellowstone microbe finding work as a CO2 scrubber. Sure, it would
mean royalties for the park, but turning philosophical for a moment, she said it's projects like
Cooksey's that make her glad Yellowstone National Park was set aside for future generations.
"When the park was created in 1872, they certainly weren't thinking of a CO2 scrubber for a coal-fired
power plant," Deutch said. "Who'd have known?"
Annette Trinity-Stevens is the MSU Research Editor.