'Bugs' cling to life in caves - Exotic bacteria survive in extreme environments

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'Bugs' cling to life in caves
Exotic bacteria survive in extreme environments

By Jim Erickson, Rocky Mountain News
October 18, 2003

GLENWOOD CAVERNS - Hazel Barton squeezes headfirst through a rock crevice and
emerges into a 20-foot-high chamber with 4-foot stalactites hanging from the
ceiling and cream-colored flowstone coating the walls like melted cake icing.

"This is why you want to be a cave explorer. Coming into a room like this when
you don't know what's in here or where it's going, but you know you're the
first person to see it.

 
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"It's what we call the man-on-the-moon feeling," said Barton, a microbiologist
who has mapped about two dozen caves.

The room, in a remote section of Glenwood Caverns closed to the public, is
decorated with showy mineral formations but appears devoid of life. Just rock
and the endless slow drip and trickle of water.

But an unseen community of dozens of types of bacteria clings to the walls,
living in total darkness and somehow eking out an existence 150 feet below the
summit of Iron Mountain in Glenwood Springs.

Barton wants to know how these bacteria survive in what appears to be a barren,
nutrient-starved environment. They are members of a class of hardy microbes
known as extremophiles, creatures that thrive in conditions most life forms
can't tolerate.

In recent decades, scientists have found extremophile microbes living in
scorching waters around sea-floor volcanic vents, in pools as caustic as
battery acid, inside nuclear reactors and in the cracks of rocks pulled from
several miles below the earth's surface.

Now, biologists like Barton are adding exotic cave microbes to the list of
organisms that cling to life's extreme edges. The cave studies, in turn, are
guiding researchers looking for possible abodes of life on other planets.

"The subsurface is crawling with microorganisms of all descriptions, and that
observation has really stretched our view of what is possible in fundamental
biology," said Penelope J. Boston, director of the cave and karst studies
program at the New Mexico Institute of Mining and Technology.

"We're learning what we can, here on Earth, essentially as practice for looking
for life on another planet," she said.

Inside Glenwood Caverns, Barton's studies have revealed the presence of 58
types of bacteria - 35 of which have not been seen anywhere else. 

"It's really hard to explain how you could have such a diverse community
growing here," said Barton, who started exploring caves as a child growing up
in England.

"It appears to us to be a starved world, but for bacteria it might be Club Med
down there. We just don't know enough about the microbial world."

Barton is an assistant professor of biological sciences at Northern Kentucky
University. Several years ago she worked as a postdoctoral fellow in the
laboratory of University of Colorado microbiologist Norman Pace.

There she learned molecular biology techniques, pioneered by Pace in the 1980s,
that allow microbiologists to isolate bacterial genes directly from the
environment.... (cont)