NASA bacteria discovery in arsenic lake, hype or revolution


This video from the USA says about itself:

You may have seen Internet speculation December 1, 2010 about a NASA announcement related to the search for extra-terrestrial life. The online rumors weren’t quite right.

But from a science perspective, a paper being published 2 December by the journal Science does describe a pretty amazing microbe. Scientists have discovered bacteria that can live and grow entirely off poison, arsenic (rather than the usual phosphate).

Found in California’s Mono Lake, the salt-loving bacteria, a member of the Halomonadaceae family of proteobacteria, may support NASA’s astrobiology program because it suggests that the requirements for life’s basic building blocks may be more flexible than we thought. In the lab, the researchers grew the bacteria in Petri dishes in which phosphate salt was gradually replaced by arsenic, until the bacteria could grow without needing phosphate, an essential building block for various macromolecules present in all cells, including nucleic acids, lipids and proteins. Using radio-tracers, the team closely followed the path of arsenic in the bacteria; from the chemical’s uptake to its incorporation into various cellular components.

Arsenic had completely replaced phosphate in the molecules of the bacteria, right down its DNA. The work by Felisa Wolfe-Simon and colleagues can be found online at http://www.sciencemag.org. For public information on this research, please see http://www.eurekalert.org and look for “Breaking News.”

By Robert Quigley in the USA:

NASA’s Hyped-Up Alien Life Press Conference Likely Just About Arsenic Biology

11:28 am, December 1st, 2010

You’ve got to hand it to NASA for their ability to routinely make a ruckus: Whereas many scientists struggle to elicit anything more than yawns from their audiences as they try to explain why their work matters (and, more pointedly, why it deserves tax or grant money), the whole “aliens” and “outer space” thing gives NASA a more receptive audience, and they know how to press that audience’s buttons.

In this case, though, things have gotten a little out of hand: A NASA press release on “an astrobiology finding that will impact the search for evidence of extraterrestrial life” morphed into Jason Kottke’s “Has NASA discovered extraterrestrial life?“, a question which he admitted was hyperbolic, which in turn mutated into progressively crazier herp-a-derp Internet speculation. Wired’s Alexis Madrigal tweeted, “I’m sad to quell some of the @kottke-induced excitement about possible extraterrestrial life. I’ve seen the Science paper. It’s not that.”

What is it, then? NASA’s press conference isn’t until 2pm EST tomorrow, so we won’t know for sure, but it seems to relate to the decidedly less sexy, though still intriguing, research done on organisms that use arsenic rather than phosphorus for energy.

One of the four participants in NASA’s press conference tomorrow is NASA astrobiology research fellow Felisa Wolfe-Simon, who has spent two years researching Yosemite Park’s Mono Lake, which has one of the highest natural concentrations of arsenic of any site in the world. Skymania spoke to astrobiologist Lewis Dartnell, who said, “I’m 90 per cent certain that Felisa has found something in Mona Lake and they have been able to demonstrate in some way that it uses arsenic in its metabolism rather than be poisoned by it.”

You may recall from your high school biology class that ATP, or adenosine triphosphate, is the so-called “energy currency” of the cell, and powers many key metabolic functions; key to ATP’s structure is the element phosphorus. Arsenic sits directly below phosphorus on the periodic table of elements and can do many of the same things chemically, but it’s usually poisonous to living things. Arsenic-powered organisms, then, would indeed represent different forms of life from those which we’re most familiar, both because they’d have ATP-like molecules with arsenic swapped in in phosphorus’ place and because they had evolved mechanisms such that arsenic didn’t kill them.

NASA Watch’s Keith Cowing writes that “[r]eliable sources within the Astrobiology community tell me that the announcement does indeed concern Arsenic-based biochemistry and the implications for the origin of life on Earth, how it may have happened more than once on our planet, and the implications for life arising elsewhere in the universe.”

See also here. And here.

Read the paper on the discovery here.

Bacterium grows with arsenic: here.

This is a Dutch TV video on the discovery.

NASA found an ‘alien’ bacteria that eats (usually toxic) arsenic – the bacteria even incorporates arsenic in its DNA: here. And here.

Sewage water bacteria helps fill ‘missing link’ in early evolution: here.

2 thoughts on “NASA bacteria discovery in arsenic lake, hype or revolution

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.