Life from a Deep Freeze

As if to ensure the survival of some species over long periods of drought and temperature extremes, nature has produced organisms that can exist many years in suspended animation. Last week two scientists announced that in soil samples taken from deep below the surface of Antarctica, they found frozen bacteria that may be anywhere from 10,000 to 1 million years old. When incubated, some of the bacteria not only returned to life but also reproduced.

Microbiologists Roy Cameron and Frank Morelli made their discovery by accident. The researchers, now at the Darwin Research Institute in Dana Point, Calif., had been working for the past three years on a project aimed at evaluating the environmental impact of deep drilling on Antarctica. As part of their work, they regularly analyzed the material brought up by the drills to determine what surface contaminants had seeped into the soil. Some experiments conducted on cores taken from layers of soil, rock and ice that had been laid down between 10,000 and 1 million years ago produced startling results. Several samples taken from the Ross Island core--one from a depth of 1,260 ft. --contained rod-shaped bacteria of a type not encountered in previous testing. Another, brought up in an area called New Harbor from a depth of 280 ft., carried club-shaped microbes.

Heat Shock. Following their normal procedure, the researchers sterilized the exterior of the core samples with a blowtorch, then used a sterile drill to remove sections containing the bacteria. Their precautions produced an unexpected side effect. When they examined chips from the Ross Island core under a microscope, they found that microbes were moving around. "We may have heat-shocked them out of dormancy," says Cameron. Placed in a nutrient broth, the rod-shaped bacteria continued to move about. The club-shaped organisms proved even more responsive. On a culture plate, they reproduced and set up colonies that looked to Cameron like "inactive volcanoes."

Neither Cameron nor Morelli is willing to claim categorically that their bacteria are the world's oldest living organisms. But if the ancient origin of the bacteria is finally established, it will have great implications for scientists searching for life on Mars. Even if the Viking Landers, which are scheduled to visit Mars in 1976, find no evidence of life on the planet's dry and frigid terrain, the Antarctic discovery holds out hope that living organisms--perhaps dormant--might still exist beneath the Martian surface.

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