Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Microbe From Depths Takes Life to Hottest Known Limit

15.08.2003

It may be small, its habitat harsh, but a newly discovered single-celled microbe leads the hottest existence known to science.

Its discoverers have preliminarily named the roughly micronwide speck "Strain 121" for the top temperature at which it survives: 121 degrees Celsius, or about 250 degrees Fahrenheit.

Announcing Strain 121’s record-breaking ability to take the heat in the August 15 issue of the journal Science, researchers Derek Lovley and Kazem Kashefi write, "The upper temperature limit for life is a key parameter for delimiting when and where life might have evolved on a hot, early Earth; the depth to which life exists in the Earth’s subsurface; and the potential for life in hot, extraterrestrial environments."

Previously, the upper known temperature limit for life had been 113 C (235 F), a record held by another hyperthermophilic-or extreme-heat-liking-microbe called Pyrolobus fumarii.

The work by Lovley and Kashefi, researchers at the University of Massachusetts, Amherst, was supported by the National Science Foundation’s Life in Extreme Environments program. Their NSF project may also yield clues to the formation of important ore deposits, the remediation of toxic contaminants, and more efficient recovery from petroleum reserves.

On a standard stovetop, water boils at 100 C, or 212 degrees F. Strain 121, however, comes from water at the ocean bottom, from a surreal deep-sea realm of hydrothermal vents. Heated to extremes by the earth’s magma, water there spouts forth through leaks in the ocean floor. The pressure of the immense depths prevents such hot water from turning to steam-even as it sometimes emerges at temperatures near 400 C (750 F).

The sample cultured by Lovley and Kashefi was collected about 200 miles offshore from Puget Sound and nearly a mile and a half deep in the Pacific Ocean by a University of Washington team led by biological oceanographer John Baross.

Baross’s crew, also supported by NSF, used a remotely operated submarine to retrieve it from the Pacific Ocean’s Juan de Fuca Ridge, a lightless seascape where vents called "black smokers" rise up like three- and four-story chimneys and continuously spew a blackening brew laced with iron and sulfur compounds.

While suffocating, crushing, scalding, toxic and downright abysmal by most living standards, the arrangement is not so bad for Strain 121 and its ilk. They are archaea, singlecelled microbes similar to, but not quite, bacteria. They often live amid extreme heat, cold, pressure, salinity, alkalinity, and/or acidity.

Archaea literally means "ancient," and Lovley and other biologists tend to call them "deep branchers" because these microbes were among the first branches on the "tree of life." According to Lovley, Strain 121-it will be given a species name after his lab finalizes the microbe’s description-uses iron the way aerobic animals use oxygen.

"It’s a novel form of respiration," Lovley says, explaining how Strain 121 uses iron to accept electrons. (Many archaea also use sulfur). As oxygen does in humans, the iron allows the microbe to burn its food for energy. Chemically, the respiration process reduces ferric iron to ferrous iron and forms the mineral magnetite.

The presence of vast deposits of magnetite deep in the ocean, its presence as a respiratory byproduct of some archaea, and the abundance of iron on Earth before life began all led Lovley and Kashefi to write that "electron transport to ferrous iron may have been the first form of microbial respiration as life evolved on a hot, early Earth."

The researchers tested the process with Strain 121 cultures kept at 100 C in oxygen-free test tubes.

"It really isn’t technically difficult. You just need some ovens to get it hot enough-and remember not to pick it up with your bare hands," Lovley says, speaking from experience. They discovered that Strain 121 grew at temperatures from 85121 C (185-250 F). (Meanwhile, Pyrolobus fumarii, the former top-temperature record-holder, wilted. After an hour at 121 C, only 1 percent of its cells were intact and none appeared viable).

"Growth at 121 C is remarkable," report Lovley and Kashefi, "because sterilization at 121 C, typically in pressurized autoclaves to maintain water in a liquid state, is a standard procedure, shown to kill all previously described microorganisms and heat-resistant spores."

Not only did Strain 121 survive such autoclaving, its population doubled in 24 hours at such heat and pressure. While they could not detect growth at higher temperatures, the researchers found that cultures that spent two hours at 130 C (266 F) still grew when transferred to a fresh medium at 103 C (217 F), with each new single-celled member appearing like a tiny tennis ball filled with cytoplasm and covered with about a dozen whip-like flagella.

Sean Kearns | NSF
Further information:
http://www.nsf.gov/home/crssprgm/lexen/start.htm
http://www.nsf.gov/od/lpa/news/03/pr0376.htm
http://www.nsf.gov/od/lpa/news/02/pr02100.htm

More articles from Life Sciences:

nachricht Mass spectrometry sheds new light on thallium poisoning cold case
14.12.2018 | University of Maryland

nachricht Protein involved in nematode stress response identified
14.12.2018 | University of Illinois College of Agricultural, Consumer and Environmental Sciences

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>