Organisms that thrive in the harshest environments on the planet,
ranging from thedry, frigid desert of Antarctica
to geyser-like hydrothermal vents spewing toxic
chemicals from the ocean floor, called ‘extremophiles’,
have long fascinated scientists.
Now, researchers from the University of Delaware and the University
of California at Riverside have thawed ice estimated
to be at least a million years old from above
Lake Vostok, an ancient lake that lies hidden
more than two miles beneath the frozen surface
of Antarctica.
Hostile
environment
Their mission is to study how microbes have survived
in the ice and become adapted to an environment
that is eternally dark, cold and so isolated that
food and energy sources are rare and hard to come
by.
The Vostok water contains only between 10- 100
microbes per ml compared to approximately 1 million
microbes per ml for most lakes.
The research, which is sponsored by the National
Science Foundation is part of the International
Polar Year. “It’s some of the coolest
stuff I have ever worked on,” said Craig
Cary, professor of marine biosciences at UD. “We
are going to gain access to the genetics of organisms
isolated for possibly as long as 15 million years.”
Segments of a tube-like-ice core were thawed under
meticulous, “clean lab” conditions
to prevent accidental contamination.
Joint
effort
The segments of ice were cut
from an 11,866-foot ice core drilled in 1998 through
a joint effort involving Russia, France and the
United States. The core was taken from approximately
2 km below the surface of Antarctica and 200 meters
above the surface of Lake Vostok.
“We have no direct samples of the lake itself,
only this indirect sampling of the refrozen ice
above it because drilling into the lake without
taking extensive precautions could lead to the
lake’scontamination.
The borehole made to collect
the ice is filled with a mixture of jet fuel,
kerosene, and CFC’s to keep it from closing
Cary noted.
“Sine the lake has not
had direct contact with the surface world for
at least 15 million years, this would be a contamination
of one of the most pristine environments on Earth,”
he said.
Novel “whole genome amplification”
techniques will be applied, which provide insight
into the genetic diversity of a community of organisms
when only small numbers of organisms are available,
according to a University of Delaware press release.
Natural
furnaces
In the case of Lake Vostok, scientists
speculate that it stays in a liquid state under
neath miles of ice due to one of the Earth’s
natural “furnaces”-hydrothermal vents.
Superheated water erupts from these cracks in
the sea floor which form where the plates that
form the Earth’s crust pull apart.
“We hope that by being
so isolated for millions of years, these microorganisms
from Vostok will be able to tell us about their
life and conditions through the ages,” Cary
said.
(SOURCE:
"The Hindu " Dated: 29 Nov. 2007)
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