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`Microbial observatories' study the invisible world of the very small

WASHINGTON—While astronomers use telescopes to observe huge, far-off galaxies, biologists are building a network of "microbial observatories" to study the invisible, mostly unknown world of the very small and near.

Scientists estimate that 99 percent of the microbes—some helpful, some harmful—that inhabit every nook and cranny on Earth have never been identified.

"The vast majority of undescribed life forms on Earth are microorganisms," said Matt Kane, the director of the Microbial Observatories program at the National Science Foundation, a government agency in Arlington, Va. "This reservoir of diversity remains largely a mystery."

Researchers say these tiny, one-celled creatures—measured in millionths of an inch—can be a rich source of new drugs that would be able to resist the bacteria that are overwhelming many of today's medicines.

"New classes of antibiotics will come from new classes of microorganisms which we know exist in nature but we don't have access to," said Slava Epstein, a microbiologist at Northeastern University in Boston.

Epstein leads an NSF microbial observatory that's collecting marine organisms from a mile-deep trench off the coast of Venezuela. Some of his little bugs are covered with bacteria, but some aren't. The clean ones, he said, must have evolved ways to control germs, a trick that humans may be able to copy.

"We should look for what kind of tools these organisms have acquired to do this," Epstein said.

Because of the difficulty and importance of the work, Kane called microbial research "one of the grand challenges facing biologists in the 21st century." Since 1999, he said, the NSF has sponsored 48 microbial observatories at a total price of $35 million. Up to 10 more projects, costing $6.6 million, will be added this year.

As the name implies, microbial observatories cost much less than astronomical projects. They also have applications a lot closer to home.

Early in August, for example, Russell Hill, a microbiologist at the University of Maryland, Baltimore, will board a small boat in Key Largo, Fla., don flippers and a face mask, and dive to an underwater reef to collect sponges, which grow profusely there. Back on shore, he'll grind up the sponges, extract billions of bacteria living inside and take them back to his lab to study their DNA.

According to Hill, these bacteria churn out toxic molecules that protect their spongy homes from fish, algae or other predators. The same molecules may work as medicines for humans.

"Sponges are the single most important marine source of new antiviral, antibacterial and antichemical drugs," Hill said. Several are being tested for use against cancer, malaria and Alzheimer's disease.

Besides finding new antibiotics, the observatories are exploring the ways that microbes affect the food supply, the environment, industry and even the possibility of life on other worlds.

James Gannon, a biologist at the University of Montana in Missoula, is the lead scientist for the Nyack Microbial Observatory, which is on a floodplain created by the Flathead River in Glacier National Park.

The floodplain is home to grizzly bears, gray wolves, bull trout and other wildlife, Gannon said. "But their invisible, essential partners, the microbes, are no less important."

He explained how it works: About 30 percent of the river water seeps into a shallow aquifer beneath the forest floor, picking up nutritious chemicals on the way and nourishing hordes of microbes. When the underground stream rejoins the river, aquatic insects gobble the microbes, fish snap up the insects and animals dine on the fish.

This kind of subsurface environment, found throughout the world, is crucial to "maintain and rejuvenate all life in the river corridor," Gannon said. "Despite their importance, these microorganisms are largely unknown. Understanding who they are is the overarching goal of the Nyack Microbial Observatory."

A research team headed by Katrina Edwards, a microbiologist at Woods Hole Oceanographic Institution in Woods Hole, Mass., uses remote-controlled submarines off the coast of Hawaii to study underwater bacteria that obtain food and energy by combining iron and oxygen. This is a process that may have been crucial to the origin of life on Earth and perhaps on iron-rich Mars.

"The microbial iron cycle could have significant implications for understanding any biological processes that may have occurred on the Red Planet," Edwards said in an e-mail message.

"We are opening a wide window onto the immense, unexplored realm of the smallest, least-known, but most important life forms," she wrote in the March issue of Oceanus, a Woods Hole publication. "Without microorganisms, there would be no other life on Earth."

Since the observatory program began, tens of thousands of new species of microbes have been discovered.

For example, some ancient bacteria were found—cold and hungry—2 miles below the surface of a 120,000-year-old glacier in Greenland. Jean Brenchley, a microbiologist at Pennsylvania State University in University Park, the lead scientist for the Greenland microbial observatory, was able to revive them.

The Greenland bacteria were extremely small—less than 8 millionths of an inch in diameter. Scientists are trying to understand how microbial life can survive in polar ice sheets despite subzero temperatures, high pressure, low oxygen and little or no food.

Brenchley said her work could help "define the limits for life" in extreme conditions on Earth or on a frigid planet such as Mars.

Some other microbial observatories:

_Gary King, an oceanographer at the University of Maine in Orono, is studying how bacteria act as "pioneering colonists" to regenerate plant life in the barren ash and lava of the Kilauea volcano on the Big Island of Hawaii. "These systems are unique because they begin with essentially nothing," King said. "This is really fun stuff."

_Mark Schneegurt, a biologist at Wichita State University in Wichita, Kan., is part of a team that's establishing an observatory in the Salt Plains National Wildlife Refuge in northern Oklahoma. The researchers are studying microbes that thrive in the dried-up remains of a briny sea that once covered much of middle America. They think it's important to understand how life can exist in such an extreme environment.

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For more information online, go to www.nsf.gov/bio/pubs/awards/mo.htm.

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(c) 2005, Knight Ridder/Tribune Information Services.

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