It was a provocative finding: strange bacteria in a California lake that thrived on something completely unexpected—arsenic. What it suggested is that life, a very different kind of life, could possibly exist on some other planet.
The research, published by a leading scientific journal in 2010, led to overheated speculation about how life might exist elsewhere—and quickly some dissent about the original finding.
On Sunday, that same journal, Science, released two papers that rip apart the original research. They "clearly show" that the bacteria can't use arsenic as the researchers claimed, said an accompanying statement from the journal.
For both new papers, scientists did their own tests of the bacteria. One team, led by Rosemary Redfield of the University of British Columbia in Vancouver, Canada, reports that arsenic does not contribute to the bacteria's growth. Maybe the original results came from some sort of undetected contaminant in the arsenic the researchers used, they suggest.
The other paper, from Swiss researchers, finds the bacteria to be highly resistant to the poisonous effects of arsenic but still dependent on phosphorus to grow. They concluded that in the original experiment, trace contamination with phosphorous may have let the bacteria grow.