Single Species Ecosystem Gives Hope For Life on Other Planets


The discovery of solitary little critters deep beneath Earth’s surface has set the world of microbiology on its head while exciting astrobiologists about the possibility of life on other planets. A community of bacteria was found 2.8 kilometers below ground in a goldmine and it lives completely alone and completely independent of any other life forms. It also subsists without sunlight or oxygen. Planetary scientist Chris McKay, of NASA’s Ames Research Center says that the species Candidatus Desulforudis audaxviator is an amazing discovery, and represents the kind or organism that could survive below the surface of Mars or Saturn’s sixth largest moon Enceladus.

Nicknamed “the bold traveler,” the species was found in fluid-filled cracks of the Mponeng goldmine in South Africa. The discovery of the species contradicts the principle that all life on earth is part of one great, interdependent system.

Scientists extracted all of the DNA present within 5,600 liters of fluid from a fracture deep within the mine. Expecting to find a mix of species within the fluid, the researchers were surprised to find that 99.9% of the DNA belonged to one bacterium, a new species. The remaining DNA was contamination from the mine and the laboratory.

A community of a single species is almost unheard of in the microbial world. But this little bacteria has been happily living on its own and seems to have all of the genetic machinery to enable it to survive independently. Since it is the only species in the ecosystem, it must extract everything it needs from an otherwise dead environment.

Analysis by Dylan Chivian of the Lawrence Berkeley National Laboratory showed that D. audaxviator gets its energy from the radioactive decay of uranium in the surrounding rocks. It has genes to extract carbon from dissolved carbon dioxide and other genes to fix nitrogen, which comes from the surrounding rocks. Both carbon and nitrogen are essential building blocks for life as we know it.

D. audaxviator can also protect itself from environmental hazards by forming endospores – tough shells that protect its DNA and RNA from drying out, toxic chemicals and from starvation. It has a flagellum to help it navigate.

Every other species that we know of on Earth planet relies on other species for some benefit. For example, humans rely on plants to photosynthesize so that we can eat them. Also, other known ecosystems on Earth that don’t use sunlight directly, such as lifeforms found in deep sea vents, do use some form of photosynthesis. But this newly found species actually can’t handle oxygen

The water in which D. audaxviator lives has not seen the light of day in over 3 million years, and this could be an indication of how old the species is.

When we start to look for life on other planets, the discovery of this species will help broaden the horizons of our search.

Abstract detailing the discovery.

Sources: New Scientist

22 Replies to “Single Species Ecosystem Gives Hope For Life on Other Planets”

  1. Honestly how would we benefit from the knowledge of there being bacteria under a rock on Mars? The reason I ask is because with funding being cut all across the nation I know for sure Science and Exploration will get hit the hardest, do you really feel that this is absolutely essential to our understanding of our surroundings and future.

  2. Diaz, dont you want to know if we are alone?

    I know want to know!

    This is an amazing discovery. Thanks for the article Nancy.

  3. LLDIAZ,
    its quite simple really. I agree the underlying info of a species of microbes under a rock on mars doesn’t really mean alot to us individually, but as a race, the discovery of even a simple microbial species somewhere else gives us an indication that life should be a lot more common that previously thought

  4. @LLDIAZ
    I think it also shows the ability of life to exist and adapt. Little Bacteria aren’t the show stopping biped, but it is an indication that there is a whole lot more out there, and for that matter on this rock, that we find flies in the face of ‘known theory’.
    An independent species, with no dependence on anything else, suggests the same could happen elsewhere, and who knows, that may for the basis for something that is dependant on it and so on .. or a larger organism that is independent of other ‘expected’ norms .. it’s all a matter of imagination and substantially increases the likelihood of life on other planets.

  5. i’ve read elsewhere that people were already speculating about making some corn with this bug’s DNA in it so the corn could fix its own nitrogen instead of using fertilizers that are bad for the environment.

  6. Whenever I see someone questioning the usefulness of a bit of basic research, I say something like this:

    A little over 100 years ago, there was a curious phenomenon that was basicly useless, except as a way to impress the ladies with a handful of neat tricks in high society saloons. Other than that it tended to raise some eyebrows that someone was silly enough to devote time, money and effort to its study.

    That phenomenon is called electricity.

    The bottom line is: in basic research we can never know beforehand what will indeed be as useless as it may seem at first glance and what will be the electricity of the future.

  7. “LLDIAZ Says:
    October 14th, 2008 at 11:17 am

    “Honestly how would we benefit from the knowledge of there being bacteria under a rock on Mars? ”

    The implications of finding life ON ANOTHER PLANET would be Earth-shattering! It may not be of any economic or social benefit, but the philosophical implications are mind-blowing. If there is life there, then this implies that life has either traveled within the solar system in the distant past, or has arisen independently in two separate places in the one solar system, despite the odds.

    Either way – this is astounding. If life is found anywhere else in the universe, even if it is just small microbes within the solar system, then the previously completely unknown likelihood of more complex life having arisen in other parts of the universe firms up as being fairly likely.

    There isn’t much that could be done in science that is more profound than that.

  8. The real issue is whether this represents another independent creation of life or is it a distant descendent of all other life on earth. If it is a second independant development of life then it is truely a milestone and shows that life can and will develop given even limited resources.

  9. yes there is life on other planets… we may never be able to find/prove it, but either way it’s still out there. So what?

  10. Now that those bacteria have been liberated from their underground lair I sure hope they don’t take a fancy to eating brains.

  11. It extracts energy from radioactive decay??? That’s VERY hard to swallow (pun intended). I’m completely unaware of ANY organism on Earth that does this. Very unlikely.

  12. Please, Please, open your minds to posibilties.
    Not everything need be measured in Dollars and cents.
    And before anyone jumps on me , yes I am aware that it takes money to do research, but the results can have implications that transcend the cost.
    The discovery of a life form completely different from anything we know here already implies that we “may” not be alone in the Universe.
    We are “Now Aware” that such a thing exists as an organism that extracts its energy from radioactive decay.
    Free your mind and your “rear” will follow!!!

  13. Further to M. Diaz’s comments and responses thereto, and understanding that that “it lives completely alone and completely independent of any other life forms”, I think that I will go and joing them, considering today’s geopolitical socio-economic conditions.

  14. neoguru Says “It extracts energy from radioactive decay??? That’s VERY hard to swallow (pun intended). I’m completely unaware of ANY organism on Earth that does this. Very unlikely.”

    Well, one other organism is known to do me. But they do not consume it in situ. Rather, they first make water cook with energy from radioactive decay and then they use the steam to have their turbines run.

    But I also do not know any organism which is not punished by mother nature on pain of death if consuming radioactive decay directly.

  15. Kenn, that is freaking awesome!

    (If that would already been known during Cold War the “day after survival kit” surely would have contained a can of Crytococcus neoformans, but presumably they do not taste like beef steak)

  16. well, its a new discovery, from 3 million year water, much older than any of us, we still havent discovered everything on earth, plus this bacteria could teach us something so we can use it in our benefit. great discovery.

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