Featured Research

from universities, journals, and other organizations

Life In The Inferno: Researchers Identify Factors That Determine Where Microorganisms Can Survive In The Hellish World Deep Underground

Date:
December 22, 1999
Source:
Idaho National E & E Laboratory
Summary:
Subsurface scientists have begun to identify the factors that determine why microorganisms survive deep underground in some places, but not others, report researchers from the Department of Energy's Idaho National Engineering and Environmental Laboratory and Princeton University.

Even Dante would blanch at the conditions kilometers below the earth's surface. Temperatures climb past 100 degrees Celsius, pressures hundreds of times greater than atmospheric pressure bear down, and space is so tight even microorganisms can barely budge.

Yet, even there life persists. Now subsurface scientists have begun to identify the factors that determine why microorganisms survive deep underground in some places, but not others, report researchers from the Department of Energy's Idaho National Engineering and Environmental Laboratory and Princeton University. The INEEL specializes in subsurface science as part of its environmental mission.

High temperatures ensure nothing can live too far below the earth's surface. But pressure, the availability of water, the porosity of the surrounding rock and the flow of chemical nutrients also limit where extremophiles--microorganisms that relish harsh conditions--can exist.

As recently as the 1980s most microbiologists thought nothing could survive far below the soil layer. They now know extremophiles live embedded in rock hundreds of meters below dry land, in deep ocean sediments and in fissures crisscrossing the ocean floor.

"We're at the point of recognizing that microorganisms have remarkable abilities to colonize these environments and trying to understand the parameters that control that colonization," said INEEL microbiologist Rick Colwell, who presented a synthesis of recent findings in the Biogeoscience: Deep Biospheres: Where and How? poster session today at the American Geophysical Society meeting in San Francisco.

A better understanding of how extremophiles survive deep underground may shed light on how life endured the earth's violent youth, or show scientists where to look for life on other planets, said Princeton geochemist T.C. Onstott.

Temperature appears to be the primary factor in limiting how deep extremophiles can go. No known microorganism can live for long at 120 degrees Celsius. Since the surface temperature averages 15 degrees Celsius and the temperature in the ground increases with depth about 19 degrees Celsius every kilometer, extremophiles should die off between five and six kilometers below the surface of dry land.

Near geothermal hotspots, subsurface temperatures rise much more rapidly, and life survives only near the surface. In deep ocean sediments, where kilometers of cold water above keep temperatures down, extremophiles may thrive at depths of several kilometers below the ocean floor.

Pressure limits the range of extremophiles less than temperature does. Most microorganisms can survive pressure 600 times atmospheric pressure, which corresponds to a depth of six kilometers. At that depth in most locations the temperature likely exceeds 120 degrees Celsius.

Lack of water and chemical nutrients likely prohibits deep subsurface life in arid, geologically stable regions. For instance, little grows between the surface and the groundwater of the Snake River Plain, on which INEEL sits.

Conversely, extremophiles may be more abundant deep in active geological features, such as faults, mid-ocean ridges and salt deposits, where fluids and nutrients flow more freely.

Subsurface environments are so austere some extremophiles live in a state of nearly suspended animation. Microorganisms living on the surface divide after hours or days. Those living deep underground may divide only after hundreds of thousands of years.

Life may have persevered below the surface 4 billion years ago, when asteroids routinely pelted the earth and caused the oceans to boil, Onstott said, so microorganisms living deep underground may provide clues about the emergence of life on the developing planet. "If you want to understand primitive microbial ecosystems, the only place you can go is into the subsurface," he said.

If life exists elsewhere in the solar system, it may be tucked beneath the surface of other planets or their moons. By studying subsurface extremophiles on earth, researchers may learn where to look in their search for extraterrestrial life.

As data accumulate, researchers hope to understand the processes that control life deep below the surface well enough to predict what they will find in a given locale. "In the early days it was discovery-driven science--let's drill a hole and see what we find," Colwell said. "I think it's now moving into what I'd call hypothesis-driven science."

Onstott agrees. "In terms of microbiology," he said, "I think the field is headed toward identifying energy sources for these microorganisms, correlating these sources to microbial activity and determining whether that activity has changed the subsurface environment."

The INEEL is managed and operated by Bechtel BWXT, Idaho, LLC (BBWI) for the U.S. Department of Energy.


Story Source:

The above story is based on materials provided by Idaho National E & E Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

Idaho National E & E Laboratory. "Life In The Inferno: Researchers Identify Factors That Determine Where Microorganisms Can Survive In The Hellish World Deep Underground." ScienceDaily. ScienceDaily, 22 December 1999. <www.sciencedaily.com/releases/1999/12/991222075443.htm>.
Idaho National E & E Laboratory. (1999, December 22). Life In The Inferno: Researchers Identify Factors That Determine Where Microorganisms Can Survive In The Hellish World Deep Underground. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/1999/12/991222075443.htm
Idaho National E & E Laboratory. "Life In The Inferno: Researchers Identify Factors That Determine Where Microorganisms Can Survive In The Hellish World Deep Underground." ScienceDaily. www.sciencedaily.com/releases/1999/12/991222075443.htm (accessed August 1, 2014).

Share This




More Plants & Animals News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Vaccine Might Be Coming, But Where's It Been?

Ebola Vaccine Might Be Coming, But Where's It Been?

Newsy (Aug. 1, 2014) Health officials are working to fast-track a vaccine — the West-African Ebola outbreak has killed more than 700. But why didn't we already have one? Video provided by Newsy
Powered by NewsLook.com
Study Links Certain Birth Control Pills To Breast Cancer

Study Links Certain Birth Control Pills To Breast Cancer

Newsy (Aug. 1, 2014) Previous studies have made the link between birth control and breast cancer, but the latest makes the link to high-estrogen oral contraceptives. Video provided by Newsy
Powered by NewsLook.com
Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Florida Panther Rebound Upsets Ranchers

Florida Panther Rebound Upsets Ranchers

AP (July 31, 2014) With Florida's panther population rebounding, some ranchers complain the protected predators are once again killing their calves. (July 31) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins