Biologically active substances 'can replace phosphorous with arsenic'

The search for life beyond the limits of the planet Earth has taken a new turn with the news that arsenic may be able to take the place of phosphorous in biologically active substances.

Although arsenic is a poison to humans, researchers from Arizona State University have looked into the potential for it to have beneficial properties in biologically active substances.

They found that GFAJ-1, a strain of the Halomonadaceae family of Gammaproteobacteria, is able to grow on a diet containing very little phosphorous but a larger amount of arsenic.

As arsenic is immediately below phosphorous on the periodic table of the elements, they had suspected that it may be advantageous to life forms in some unusual environments on Earth - and possibly in other parts of the universe.

The findings are published in Science Express, the ahead-of-print periodical which provides a preview of papers due for dissemination in the journal Science.