Researchers question the science behind last week’s revelation of arsenic-based life

From Nature:

Days after an announcement that a strain of bacteria can apparently use arsenic in place of phosphorous to build its DNA and other biomolecules — an ability unknown in any other organism — some scientists are questioning the finding and taking issue with how it was communicated to non-specialists.

Many readily agree that the bacterium, described last week in Science and dubbed GFAJ-1 (F. Wolfe-Simon et al. Science doi:10.1126/science.1197258; 2010), performs a remarkable feat by surviving high concentrations of arsenic in California's Mono Lake and in the laboratory. But data in the paper, they argue, suggest that it is just as likely that the microbe isn't using the arsenic, but instead is scavenging every possible phosphate molecule while fighting off arsenic toxicity. The claim at a NASA press briefing that the bacterium represents a new chemistry of life is at best premature, they say. “It's a great story about adaptation, but it's not ET,” says Gerald Joyce, a biochemist at the Scripps Research Institute in La Jolla, California.

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