[meteorite-list] Arsenic Bacteria Hoax

[JoshuaTreeMuseum]

Turns out it was a bogus publicity stunt:
http://www.washingtonpost.com/national/health-science/journal-retreats-from-controversial-arsenic-paper/2012/07/08/gJQAFQb7WW_story.html?hpid=z3

Journal retreats from controversial arsenic paper



By Marc Kaufman, Updated: Sunday, July 8, 10:05 PMThe Washington Post
Two new studies of controversial research on a bacterium found in California's 
arsenic-rich Mono Lake led the journal Science on Sunday to say that the 
2010 paper it published on the microbe was incorrect in some of its major 
findings.
The original research, which also had been highlighted by NASA, reported 
that the bacterium could live in an environment with very high arsenic and 
very low phosphorus - one of the six elements known to be present in all 
living things. It consequently raised the possibility of life forms now or 
previously on Earth that break what had been accepted as a universal rule of 
biology.

But two new studies of the bacterium, GFAJ-1, reported that it could not 
grow without the presence of phosphorus. The ­papers also challenged the 
original finding that small amounts of arsenic compounds had replaced 
phosphorus compounds in some DNA, membranes and other biologically central 
parts of the organism.
"Contrary to an original report, the new research clearly shows that the 
bacterium, GFAJ-1, cannot substitute arsenic for phosphorus to survive," the 
journal concluded in a formal statement.
"The new research shows that GFAJ-1 does not break the long-held rules of 
life, contrary to how [lead author Felisa] Wolfe-Simon had interpreted her 
group's data."
Nonetheless, Science wrote that it would look with interest at further 
research regarding the bacterium, which it called "an extraordinarily 
resistant organism that should be of interest for further study, 
particularly related to arsenic-tolerance mechanisms."
Wolfe-Simon, now on a NASA fellowship at the Lawrence Berkeley National 
Laboratory, is collaborating with senior scientist John A. Tainer on 
wide-ranging studies of the bacterium. In an interview Saturday, Wolfe-Simon 
and Tainer said that they had produced tentative results in the Berkeley lab 
almost identical to the original results at a U.S. Geological Survey 
laboratory, and that they were busy finishing the research and preparing 
another paper.
Tainer said the two new studies in Science may have come to different 
results than theirs because of the methodologies used, the precision used to 
detect arsenates and the provenance of the cells. He said the authors of the 
two new papers "may well regret some of their statements" in the future.
"There are many reasons not to find things - I don't find my keys some 
mornings," he said. "That doesn't mean they don't exist. The absence of a 
finding is not definitive."
Wolfe-Simon and her numerous collaborators had made samples of GFAJ-1 
broadly available after her initial results caused a storm of controversy, 
but she and Tainer said they may have been contaminated or modified in 
transit.
She said that all the researchers agreed that the bacterium survived in 
extraordinarily high levels of usually toxic arsenic compounds but that they 
disagreed about whether the organism used the arsenic compound to grow and 
whether it had incorporated the arsenic into its biology.
"I think it's unclear whether this is the last word," ­Wolfe-Simon said. 
"They're not finding something that could be there in a minor amount."
One of the new studies in Science was conducted by a team centered at 
Princeton University that included Rosemary Redfield of the University of 
British Columbia. She was one of the first and most vocal critics of the 
original Wolfe-Simon paper, and she said Sunday she was satisfied with how 
the process has played out.
"A very flawed paper was published and received an inordinate amount of 
publicity," she wrote in an e-mail. "But other researchers responded very 
quickly. .?.?. Now refutations of the work by two independent research 
groups are appearing in the same high-profile journal, and the refutations 
are being well publicized. This is how science is supposed to work."
The new study Redfield was part of did not find any microbial growth when 
arsenates were provided to the bacteria without phosphates. Wolfe-Simon had 
initially reported that the bacterium grew when phosphorus compounds were 
withheld but arsenic compounds were provided. The new study also found no 
biologically mediated arsenic in the microbe's DNA, as ­Wolfe­Simon had 
reported.
The paper concludes that the bacterium is an extreme life form but one that 
has adapted to its environment in a manner similar to many others that live 
in conditions long thought to be unsuitable for life.
The second new study in Science came from a research group in Switzerland. 
That group also found no growth in the bacteria in a medium with arsenic 
compounds but no phosphorus. The paper suggested that Wolfe­Simon's initial 
finding may have missed the presence of extremely small amounts of 
phosphorus in the arsenic medium, which then allowed the bacterium to grow.
The paper reported that the GFAJ-1 bacteria survived in a culture that had a 
ratio of arsenate to phosphate of 10,000 to 1, while other known 
arsenic-resistant microbes had ratios that were much lower. As a result, 
they concluded, the bacteria was a good candidate for further study.

Phil Whitmer
Joshua Tree Earth & Space Museum










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