Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Microbe From Depths Takes Life to Hottest Known Limit


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:

More articles from Life Sciences:

nachricht Don't Give the Slightest Chance to Toxic Elements in Medicinal Products
23.03.2018 | Physikalisch-Technische Bundesanstalt (PTB)

nachricht North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>