NASA-Funded Research Discovers Life Built With Toxic Chemical

[Grat3fulh3ad]

NASA-funded astrobiology research has changed the fundamental knowledge about what comprises all known life on Earth.

Researchers conducting tests in the harsh environment of Mono Lake in California have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism substitutes arsenic for phosphorus in its cell components.

"The definition of life has just expanded," said Ed Weiler, NASA's associate administrator for the Science Mission Directorate at the agency's Headquarters in Washington. "As we pursue our efforts to seek signs of life in the solar system, we have to think more broadly, more diversely and consider life as we do not know it."

This finding of an alternative biochemistry makeup will alter biology textbooks and expand the scope of the search for life beyond Earth. The research is published in this week's edition of Science Express.

Carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur are the six basic building blocks of all known forms of life on Earth. Phosphorus is part of the chemical backbone of DNA and RNA, the structures that carry genetic instructions for life, and is considered an essential element for all living cells.

Phosphorus is a central component of the energy-carrying molecule in all cells (adenosine triphosphate) and also the phospholipids that form all cell membranes. Arsenic, which is chemically similar to phosphorus, is poisonous for most life on Earth. Arsenic disrupts metabolic pathways because chemically it behaves similarly to phosphate.

"We know that some microbes can breathe arsenic, but what we've found is a microbe doing something new -- building parts of itself out of arsenic," said Felisa Wolfe-Simon, a NASA Astrobiology Research Fellow in residence at the U.S. Geological Survey in Menlo Park, Calif., and the research team's lead scientist. "If something here on Earth can do something so unexpected, what else can life do that we haven't seen yet?"

The newly discovered microbe, strain GFAJ-1, is a member of a common group of bacteria, the Gammaproteobacteria. In the laboratory, the researchers successfully grew microbes from the lake on a diet that was very lean on phosphorus, but included generous helpings of arsenic. When researchers removed the phosphorus and replaced it with arsenic the microbes continued to grow. Subsequent analyses indicated that the arsenic was being used to produce the building blocks of new GFAJ-1 cells.

The key issue the researchers investigated was when the microbe was grown on arsenic did the arsenic actually became incorporated into the organisms' vital biochemical machinery, such as DNA, proteins and the cell membranes. A variety of sophisticated laboratory techniques was used to determine where the arsenic was incorporated.

The team chose to explore Mono Lake because of its unusual chemistry, especially its high salinity, high alkalinity, and high levels of arsenic. This chemistry is in part a result of Mono Lake's isolation from its sources of fresh water for 50 years.

The results of this study will inform ongoing research in many areas, including the study of Earth's evolution, organic chemistry, biogeochemical cycles, disease mitigation and Earth system research. These findings also will open up new frontiers in microbiology and other areas of research.

"The idea of alternative biochemistries for life is common in science fiction," said Carl Pilcher, director of the NASA Astrobiology Institute at the agency's Ames Research Center in Moffett Field, Calif. "Until now a life form using arsenic as a building block was only theoretical, but now we know such life exists in Mono Lake."

The research team included scientists from the U.S. Geological Survey, Arizona State University in Tempe, Ariz., Lawrence Livermore National Laboratory in Livermore, Calif., Duquesne University in Pittsburgh, Penn., and the Stanford Synchroton Radiation Lightsource in Menlo Park, Calif.

NASA's Astrobiology Program in Washington contributed funding for the research through its Exobiology and Evolutionary Biology program and the NASA Astrobiology Institute. NASA's Astrobiology Program supports research into the origin, evolution, distribution, and future of life on Earth.

 

[HempKat]

Actually they didn't discover life built with a toxic chemical. They created it, or more correctly altered it. At least that's what I got from reading the story.

 

[Weird]

once again science discovers fiction isn't as fictional as one would imagine

btw dont drink the mono lake water

 

[Grat3fulh3ad]

Actually they didn't discover life built with a toxic chemical. They created it, or more correctly altered it. At least that's what I got from reading the story.

Or discovered that it would self alter under a specific set of conditions.

 

[BrainSellz]

nasa needs to put its big microscope on the poverty and hunger we have going on in the world m2....no swimming

 

[Grat3fulh3ad]

nasa needs to put its big microscope on the poverty and hunger we have going on in the world m2....no swimming

I agree, but the moment a govt. funded agency does anything of the sort the crazies all start screaming socialism.

 

[Weird]

why do they want to seed life in poisonous environments

 

[Grat3fulh3ad]

why do they want to seed life in poisonous environments

because industry is making us all live in a poisoned environment?

EDIT: actually they wanted to find life in a poisonous environment, not seed it there.

 

[juicepuddle]

once again science discovers fiction isn't as fictional as one would imagine

Or as one would imagine. The way I see it science fiction is thought up in mans head, makes sense that alot of that eventually comes to fruition through different folks.

 

[sac beh]

Its not terribly wrong to say life built with a toxic chemical. Even though the conditions were created in a lab, the microbe was still able to incorporate arsenic into its life sustaining biochemistry, in place of phosphorus, which was believed to be an absolutely necessary building block of life across all life forms.

I'm anxious to see how certain conspiracy theorists will incorporate this. They had high hopes going in:

Okay...this is it people. We all know disclosure must begin on a small level before TPTB will admit to the presense of intelligent extraterrestrial life. I wonder if the ETs are pushing their hand a bit to bring about this announcment.

Lol

 

[BrainSellz]

eventually we will all turn into zombies and need to breath the arsenic that nasa will make for us. maybe they will flavor it for us also.........

 

[Weird]

because industry is making us all live in a poisoned environment

i would think to seed life in hostile space environments

it seems some life on earth adapts to poisonous environments

a parallel to why not all life is erased during past cataclysms? adaptive advantage of some organisms

 

[accessndx]

It's been known for a long time that arsenic could swap out with phosphorus. I don't recall where I read this either, but I could swear that this organism has been known about for some time. This could just possibly be one of those media hype things that NASA pulls occasionally when they need funding desperately.
Even though this may be old(er) news recycled by the media, it's nonetheless pretty darn cool. Absolutely makes the same kind of stride that the hydrothermal vents did when they were first discovered.....and broadens our ability and range to look for other forms of "life".
A big K+ to the folk that are on that cutting edge of discovery.

 

[Grat3fulh3ad]

upon reading and re reading the articles, they did indeed discover the bacteria, and the incorporation of arsenic into it's makeup is naturally occurring in the lake as well as in the lab. They're not making life to put in toxic environments, they found life in a toxic environment.

http://www.astrobio.net/exclusive/3698/thriving-on-arsenic

One of the basic assumptions about life on Earth may be due for a revision. Scientists have discovered a type of bacteria that thrives on poisonous arsenic, potentially opening up a new pathway for life on Earth and other planets.

If you thumb through an introductory biology textbook, you’ll notice that six elements dominate the chemistry of life. Carbon, hydrogen, oxygen and nitrogen are the most common. After that comes phosphorus, then sulfur. Most biologists will tell you that these six elements are essential: life as we know it cannot exist without them.

The recent discovery by Felisa Wolfe-Simon of an organism that can utilize arsenic in place of phosphorus, however, has demonstrated that life is still capable of surprising us in fundamental ways. The results of her research were published December 2 on Science Express and subsequently in the journal Science.

The organism in question is a bacterium, GFAJ-1, cultured by Wolfe-Simon from sediments she and her colleagues collected along the shore of Mono Lake, California. Mono Lake is hypersaline and highly alkaline. It also has one of the highest natural concentrations of arsenic in the world.

On the tree of life, according to the results of 16S rRNA sequencing, the rod-shaped GFAJ-1 nestles in among other salt-loving bacteria in the genus Halomonas. Many of these bacteria are known to be able to tolerate high levels of arsenic.

But Wolfe-Simon found that GFAJ-1 can go a step further. When starved of phosphorus, it can instead incorporate arsenic into its DNA, and continue growing as though nothing remarkable had happened.

“So far we’ve showed that it can do it in DNA, but it looks like it can do it in a whole lot of other biomolecules” as well, says Wolfe-Simon, a NASA research fellow in residence at the USGS in Menlo Park, California.

“It is the first time in the history of biology that there’s been anything found that can use one of the different elements in the basic structure,” says Paul Davies, the director of BEYOND: Center for Fundamental Concepts in Science at Arizona State University in Tempe, Arizona. Wolfe-Simon’s finding “can only reinforce people’s belief that life can exist under a much wider range of environments than hitherto believed,” he says. He sees the discovery of GFAF-1 as “the beginning of what promises to be a whole new field of microbiology.”

Michael New, NASA’s astrobiology discipline scientist, agrees. “The discovery of an organism that can use arsenic to build its cellular components may indicate that life can form in the absence of large amounts of available phosphorous, thus increasing the probability of finding life elsewhere,” he says. “This finding expands our understanding of the conditions under which life can thrive, and possibly originate, thereby increasing our understanding of the distribution of life on Earth and the potential habitats for life elsewhere in the solar system.

In case you’re not impressed yet, here’s a quick refresher. The DNA molecule is shaped like a spiral ladder. The “rungs” of the ladder are comprised of pairs of nucleotides, which spell out the genetic instructions of life. The sides of the DNA ladder, referred to as its backbone, are long chains of alternating sugar and phosphate molecules. A phosphate molecule contains five atoms: one of phosphorus, four of oxygen. No phosphorus, no phosphate. No phosphate, no backbone. No backbone, no DNA. No DNA, no life.

GFAJ-1 apparently didn’t read the manual.

When Wolfe-Simon starved GFAJ-1 cells of phosphorus, while flooding them with arsenic, far more than enough arsenic to kill most other organisms, it grew and divided as though it had been offered its favorite snack. Wolfe-Simon, with assistance from colleagues in Ron Oremland’s group at the USGS in Menlo Park, California, have grown generation after generation of these bacteria. The bacteria continue to swim around in their test tubes, unconcerned, despite the fact that, since Wolfe-Simon first collected them more than a year ago, the only phosphorus they have had access to was whatever was present in the original colony of cells, plus tiny traces, far too little to sustain ongoing growth and cell division, present as impurities in the cells’ growth medium.

And you thought arsenic was poison, right? To most living organisms, it is. Arsenic is chemically similar to phosphorus, so it can sneak its way into living cells, as if wearing a disguise. But it is more reactive than phosphorus, in ways that tend to rip apart life’s essential molecules. DNA, for example. Somehow, GFAJ-1 appears to have found a way to overcome this problem.

As a control, a second culture of GFAJ-1 cells was fed phosphorus instead of arsenic. They, too, grew and divided. GFAJ-1 seems able to switch back and forth, depending on how much phosphorus is available.

“I have no idea how they’re doing what they’re doing,” Wolfe-Simon says.

Once she realized that GFAJ-1 was capable of growing when starved of phosphorus, Wolfe-Simon set about finding out in more detail what was going on inside its cells. Could it be, perhaps, that she had found a microbe that, rather than incorporating arsenic into its biological structures, was instead exceptionally good at recycling extremely limited amounts of phosphorus?

Wolfe-Simon and her colleagues used several different experimental techniques to find an answer.

Data produced by mass-spectrometry methods known as ICP-MS and NanoSIMS, showing the distribution of various chemical elements within GFAJ-1 cells, revealed a clear difference between cells grown with arsenic and those grown with phosphorus. Those grown with arsenic were loaded with the stuff, but contained very little phosphorus. In cells grown with phosphorus, the opposite was true.

By introducing radioactive arsenic into the growth medium of some of the microbes, Wolfe-Simon learned that about one-tenth of the arsenic absorbed by the bacteria ended up in their nucleic acids.

To confirm that this arsenic was being incorporated into DNA, she used a well-accepted molecular biology technique known as gel purified DNA extraction to isolate and concentrate DNA from GFAJ-1 cells. The value of this technique is that it ensures that no other material from the cell comes along for the ride. NanoSIMS measurement of these concentrated DNA extractions showed that arsenic was indeed present in their DNA.

Still further evidence came from the use of a technique known as micro extended X-ray absorption fine structure spectroscopy (µEXAFS). µEXAFS can provide information about the structure of molecules by probing how its internal chemical bonds respond when stimulated by a beam of light. Within the DNA extracted from GFAJ-1 cells starved of phosphorus, it showed arsenic bonded to oxygen and carbon in the same way phosphorus bonds to oxygen and carbon in normal DNA.

In other words, every experiment Wolfe-Simon performed pointed to the same conclusion: GFAJ-1 can substitute arsenic for phosphorus in its DNA. “I really have no idea what another explanation would be,” Wolfe-Simon says.

But Steven Benner, a distinguished fellow at the Foundation for Applied Molecular Evolution in Gainesville, FL, remains skeptical. If you “replace all the phosphates by arsenates,” in the backbone of DNA, he says, “every bond in that chain is going to hydrolyze [react with water and fall apart] with a half-life on the order of minutes, say 10 minutes.” So “if there is an arsenate equivalent of DNA in that bug, it has to be seriously stabilized” by some as-yet-unknown mechanism.

Benner suggests that perhaps the trace contaminants in the growth medium Wolf-Simon uses in her lab cultures are sufficient to supply the phosphorus needed for the cells’ DNA. He thinks it’s more likely that arsenic is being used elsewhere in the cells, in lipids for example. “Arsenate in lipids would be stable,” he says, and would “not fall apart in water.” What appears in Wolfe-Simon's gel-purified extraction to be arsenate DNA, he says, may actually be DNA containing a standard phosphate-based backbone, but with arsenate associated with it in some unidentified way.

The discovery of GFAJ-1’s unusual abilities suggests a number of avenues for further research. One obvious one is to see whether any other organisms can perform similar biochemical tricks.

Wolfe-Simon “would be very unlikely to have just found the only arsenic life form on Earth on the first try. So it’s got to be the tip of a very large iceberg,” Davies says.

And indeed, Wolfe-Simon says she is already growing “14 or so other isolates” from Mono Lake on a phosphorus-free diet high in arsenic. They may be the same organism she’s already identified, they may not. “I don’t know anything else about them, except that they grow under similar conditions.”

Meanwhile, Wolfe-Simon has ordered stock cultures of several previously identified Halomonas organisms, close relatives of GFAJ-1 on the genetic tree, all known to be arsenic-tolerant. She plans to test whether they, too, can survive in a phosphorus-free environment.

She’s also interested in finding out whether GFAJ-1 is actively employing its arsenic-incorporating ability in its natural state. “You want to know, is this biology being done in the environment or is it some very bizarre thing, like a hat trick [that it does only] in the lab.”

And Davies suggests it would be interesting to search in “an environment that has very little phosphorus and lots of arsenic” for an organism that requires arsenic to survive, “for which phosphorus would be the poison.” Mono Lake, he points out, “has phosphorus as well arsenic.”

These and other investigations will help to clarify how extensive a role arsenic plays both within GFAJ-1 and in terrestrial biology as a whole. But while some scientists may reserve final judgment about Wolfe-Simon’s conclusions until further details can be clarified, even Benner concedes that “If that organism has arsenate DNA, that is a world-class discovery.”

Wolfe-Simon’s research is funded by the NASA Exobiology/Evolutionary Biology program, with additional support from the NASA Astrobiology Institute (NAI).

 

[Weird]

what if we boost the phosphorous instead?

 

[sac beh]

eventually we will all turn into zombies and need to breath the arsenic that nasa will make for us. maybe they will flavor it for us also.........

You just created the first NASA-NWO-arsenic conspiracy theory. Web sites will spring up in its honor soon enough. The theory will certainly include Monsanto and a program to breed all forms of life except the human slaves to arsenic-based in preparation for our extermination.

 

[Weird]

how do you know montasano isnt trying to program a cannabis plant to need a specific nute to grow so when they corner the seed market they can be the new AN on the block ?


I bet they own AN if you follow the paper trail far enough



and NASA!!!

 

[sac beh]

how do you know montasano isnt trying to program a cannabis plant to need a specific nute to grow so when they corner the seed market they can be the new AN on the block ?

Well, because I haven't seen proof for the claim yet. You're not going off the TY article are you?

 

[HempKat]

What I gather is the significance is this will redefine how we think of life and where we will look for it. With the vast number of stars, planets and moons we figure exist in the universe we would have to filter things out a bit when deciding where to explore. In the past we might not have bothered to look on planets with high levels of Arsenic or we might have not bothered with planets not showing signs of phosperous. Now we know that we could be wrong to assume such planets have no life on them.

 

[Grat3fulh3ad]

What I gather is the significance is this will redefine how we think of life and where we will look for it. With the vast number of stars, planets and moons we figure exist in the universe we would have to filter things out a bit when deciding where to explore. In the past we might not have bothered to look on planets with high levels of Arsenic or we might have not bothered with planets not showing signs of phosperous. Now we know that we could be wrong to assume such planets have no life on them.

Exactly. a perfectly reasonable explanation for the probable motivations for this avenue of research.