The Importance of Extremophiles

Life Survives Under Harsh and Unusual Conditions

Oct 11, 2009 Bridget Coila

Extremophiles survive harsh conditions that would otherwise be unlivable. Studying them offers clues to evolution, adaptation and the possibility of life on other worlds.

Extremophiles live in places that most life would find too extreme, from deep ocean hydrothermal vents to under Arctic ice. Their existence provides evidence for the ability of life to thrive under almost any circumstances and studying them reveals information vital to both basic biology and applied biotechnology applications.

A Simple Definition of Extremophiles

Extremophiles are organisms that live in extremely harsh environments. One of the key determiners scientists use to define these creatures is that they actually cannot live in normal environments where most life thrives. This includes conditions of extremely high or low temperature, salt content, pH or water content.

While many are bacterial in nature, belonging to the scientific kingdom Eubacteria, they aren't limited to this group. Some eukaryotes and archaebacteria are also included in this category. Dave Roberts of the London Natural History Museum Zoology Department has catalogued hundreds of eukaryotic extremophiles, including algae, worms and fungi.

Clues to the Origin of Life on Earth Provided by Extreme Organisms

In the distant past, when life first formed on Earth, conditions on the planet were not the same as now. By looking at organisms living in tough conditions, scientists can explore possible adaptations that organisms made when conditions on Earth were much harsher than today. Places like underneath Antarctic ice and inside dry desert rocks mimic conditions from early Earth, and the organisms they house have adaptations that all other life on the planet has lost.

Extremophiles and Astrobiology Research

Life on other planets isn't likely to be as comfortable as here on Earth and astrobiologists look to extremophiles to determine how exactly life elsewhere in the universe might have developed.

Some places scientist think might harbor life in the solar system include the permafrost of Mars, hydrothermal vents on Jupiter's moon Europa, the methane and ethane oceans of Saturn's moon Titan and the cloud surface of Venus.

Biotechnology Benefits from Studying Extremophiles

One of the most important discoveries in biology was a compound called Taq Polymerase, which comes from the bacteria Thermus aquaticus, found in Yellowstone's hot springs. Taq Polymerase helps the bacteria survive the near-boiling temperatures of the hot springs by controlling the breakup and reassembly of the bacterial DNA.

Now, Taq Polymerase is used in lab experiments to manipulate genetic material used in research. It is considered one of the most important tools used by modern biotechnology research labs and is a key component to the frequently used lab assay called PCR.

Compounds In Extremophiles Useful to Industry

One of the most famous extreme-living organisms among scientist today is Deinococcus radiodurans, a bacteria that can survive radiation up to 1000 times what human cells can withstand, according to the July 5, 2002 Genome News Network article "The World’s Toughest Bacterium" by Sarah E. DeWeerdt.

First discovered in irradiated canned meat, this bacteria is sometimes found in the most inhospitable places to survive on earth, including Antarctic dry valleys, elephant dung and nuclear waste sites where it survives under extremely high radiation. Scientists, including some funded by the US Department of Energy (DOE), are currently investigating ways to use the bacteria for bioremediation, the cleanup of nuclear waste sites.

Aside from the research already underway, the study of extremophiles holds vast promise for the future, too. These impressive organisms may teach scientists about past and future life on Earth, provide new compounds or biological processes for use in fields like synthetic biology and offer new views on how life could survive in places previously believed to be impossible for surviving.

The copyright of the article The Importance of Extremophiles in Biology is owned by Bridget Coila. Permission to republish The Importance of Extremophiles in print or online must be granted by the author in writing.

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