By

Charles Cooper /

CBS/AP/ December 2, 2010, 9:09 PM

Why the Arsenic-Eating Microbe is a Huge Deal

Heavy rains fall prior to the Euro 2012 soccer championship Group D match between Ukraine and France in Donetsk, Ukraine, Friday, June 15, 2012. The match was suspended after a few minutes due to the weather. (AP Photo/Vadim Ghirda)

Heavy rains fall prior to the Euro 2012 soccer championship Group D match between Ukraine and France in Donetsk, Ukraine, Friday, June 15, 2012. The match was suspended after a few minutes due to the weather. (AP Photo/Vadim Ghirda) / Vadim Ghirda

"NASA has found a new form of life? Neat. Call me when it's got heat vision, wears blue pajamas, and flies."

So one wisenheimer tweeted in reaction to the official word out of NASA that no, researchers had not made contact with an extra terrestrial. But let's not get blase' in the face of history: the discovery of a microbe that can use arsenic as one of its nutrients is a mind-blowing event.

Maybe the disappointment of some was is understandable given the hype and excitement around NASA's announcement earlier in the week that it planned a Thursday announcement connected to "an astrobiology finding that will impact the search for evidence of extraterrestrial life."

And so it was - even if the day's agenda did not include a walk-on by a google-eyed alien.

For starters, the discovery of an arsenic-eating microbe will surely force some heavy editing of scientific textbooks. The assumption has been that there are six major elements considered essential for life: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. Thursday's announcement replaces that coda with a question mark.

If phosphorus is not necessarily needed as a central component of the energy-carrying molecule in all cells, then what about the others?

"This cracks open the door," said Felisa Wolfe-Simon, whose team found evidence of the weird bacteria on the remote shores of 10 Mile Beach at Mono Lake in California.

Wolfe-Simon and a clutch of scientific colleagues, who assembled at a NASA-sponsored event in Washington Thursday afternoon to discuss the finding, were bubbling over with excitement as they discussed the findings. Whether it strikes the same chord among laymen is still unclear - though it should.

Geobiologist Pamela Conrad pointed out that the microbe in question acts very differently from "life as we knew it" in its ability to substitute arsenic for phosphorous."

To be sure, this dual ability to grow using either element qualifies as a first in the annals of science. Even though this doesn't qualify as a textbook example of a life form from another planet, it will force scientists to recalibrate their assumptions as they search for other forms of life.

Ecologist James Elser of Arizona State University disposed of understatement when he said the discovery basically shakes the heretofore bedrock assumption that organisms cannot grow without needing phosphorous.

"Every living thing uses phosphorus," he said. "To say that it's not true is shocking."

Horta Today, ET Tomorrow?

During the Q&A, one scientist recalled a "Devil in the Dark" "Star Trek" episode from 1967 which featured a silicon-based creature called the Horta. In a similar way, today's announcement challenges science's concepts about the fundamental building blocks of life.

The discovery "does show that in other planetary environments organisms might be able to use other elements to drive biochemistry and that the 'standard' set of elements we think are absolutely necessary for life might not be so fixed," commented Charles Cockell, professor at the Planetary and Space Sciences Research Institute, Open University, in Milton Keynes, United Kingdom. Cockell was not part of the research team.

"This work is novel because it shows the substitution of one element for another in fundamental biochemistry and biochemical structure," added Cockell.

It wasn't a chance discovery.

Wolfe-Simon of NASA's Astrobiology Institute, who led the study, targeted Mono Lake because it has high arsenic levels. Arsenic and phosphorous are chemically similar, so she speculated that a microbe exposed to both might be able to substitute one for the other.

"Arsenic is toxic mainly because its chemical behavior is so similar to that of phosphorus. As a result, organisms have a hard time telling these elements apart. But arsenic is different enough that it doesn't work as well as phosphorus, so it gets in there and sort of gums up the works of our biochemical machinery," explained Anbar.

The researchers collected the bacteria known as GFAJ-1 and exposed it to increasing concentrations of arsenic, which it was able to adapt to and grow.The microbe does grow better on phosphorous, but showing that it can live with arsenic instead raises the possibility that a life form using arsenic could occur naturally, either elsewhere on Earth or on another planet or moon where arsenic is more common.

Jamie S. Foster, an assistant professor of microbiology at the University of Florida, said the idea that arsenic could be substituted for phosphorous isn't new, but there has never been example where it was shown to work. Arsenic was more common in the early times on Earth, she said, so researchers have speculated that early life forms might have used it.

"It does suggest that that there could be other ways to form life, not just how life formed on early Earth," said Foster, who was not part of Wolfe-Simon's research team.

The research was supported by NASA, the Department of Energy and the National Institutes of Health.

(The Associated Press contributed to this report)
CBS/AP
  • Charles Cooper On Twitter » On Google+ »

    Charles Cooper is an executive editor at CNET News. He has covered technology and business for more than 25 years, working at CBSNews.com, the Associated Press, Computer & Software News, Computer Shopper, PC Week, and ZDNet. E-mail Charlie.

10 Comments Add a Comment
linkicon reporticon emailicon
MekhongKurt says:
I'm a little confused by the bulk of the news coverage of this story, as most of it says that these critters are out-and-out substituting arsenic for phosphorous. However, earlier today I read a science blog that said even the project scientists say that *may* be the case -- but that it also maybe the case that the microbes are storing the arsenic in isolation. If the blog is correct, then it's too early to say we have to add to the list of essential elements for life -- though I sure hope that's the case, since it would expand the possibility of life elsewhere in the Universe.

Or is that blog missing the mark? It's the only place I read what it says. (I wish I could remember which one it was, but I can't.)
reply
linkicon reporticon emailicon
maggieanne91 says:
http://xkcd.com/
reply
linkicon reporticon emailicon
mchoward21 says:
This is pretty cool but I dont get why this was never thought of before? I have always kind of wondered that just because life on Earth is based on certain elements or set up a certain way, why does it have to be the same across the universe? Couldn't different circumstances and processes have altered life to include different evolutionary traits?

It seems kind of naive and arrogant to think it HAS to be like this elsewhere.
reply
maggieanne91 replies:
linkicon reporticon emailicon
Uh... you can't just think of something to establish it as scientific fact. Of course the idea that life could develop in other ways has been though of before (the article even acknowledges that). The big deal is that living proof of alternate life has been found.
linkicon reporticon emailicon
atomant59 says:
Well how can this be? This was not in the bible? Hummm, maybe there is something to this evolution thing after all? Maybe Darwin was not so stupid after all.
reply
linkicon reporticon emailicon
rwsmith29456 says:
Without going into budget and politics let me just say that this a great find.
reply
linkicon reporticon emailicon
rdepontb says:
NASA's Public Relations office at it again. "Now they'll have to update what they're looking for in other worlds" says Lifeson2112. Just what NASA wants people to think---so they can suck up waaaayyy to much of the nation's science resources and keep those outrageous contracts going forever. Me, I've had enough---send 90% on furlough for five years.

The money and talent they expend _could_ be put to use right here Earth. But, they'd like us to believe, we can do whatever we want here---they'll find us a new place to live, and soon! Screwed up bunch of concepts and principles.
reply
MekhongKurt replies:
linkicon reporticon emailicon
@rdepontb, you clearly are unaware of the countless benefits we mere mortals -- right here on Earth -- have received through NASA's efforts over the decades. Like the computer you typed your comment on? -- a fair amount of the technology in hit comes from NASA, directly or indirectly. The same is true for various communication methods, most notably the Internet. And how about in the field of medicine? The development of composite materials is largely a direct result of NASA research combined with that of folks over on the DoD, such as in DARPA.

From the mundane to the cutting edge, NASA looms large.

I have the distinct feeling that had you been around before Columbus sailed the Atlantic, you would have been among those opposed to "wasting" money on such frivolous exploration -- as a fair number of people were. As we all know, the explorers got the last laugh there.

Or maybe you're among those who say, "Defund NASA. Send my share of the saved loot to this address: XXXXXXXXX. I'll be expecting it in a week or two."

NASA's budget has dropped dramatically over the decades, even not factoring in inflation. Adjusted for inflation, and its budget has shrunk even more than immediately evident from the raw numbers.

Many NASA folks have genuine pioneer spirits. They're not in it for the money, per se, though we all have to live. They have that unquenchable thirst to push human boundaries ever outward and beyond. Why else would astronauts climb into a spacecraft built by the lowest bidder???

No, I don't now nor ever have worked for NASA, nor have my family or friends. Therefore, I don't have a financial dog in this fight.
linkicon reporticon emailicon
seafang says:
Big deal; there's nothing new about Arsenic eating microbes; well not in the last 55 years. That's how long ago I was in a chemistry class in high school, and we had a bunch of Arsenic eating microbes just chowing down in a flask full of arsenic solution; just sitting there on the lab chemicals shelf.

So tell me something I didn't know before; this is boring.
reply
Lifeson2112 replies:
linkicon reporticon emailicon
The discovery is a microbe using arsenic as a part of its DNA instead of phosphorus. Its never been seen before and no one knew if it could be done. Now NASA will have to update what they're looking for on other worlds.