Scientists contest claims over arsenic eating bacteria

A scientific spat entered the public domain yesterday when the journal Science, in an unusual step published challenges to a report about a strange, arsenic-eating bacteria.

The authors of the study defending their position said they considered their interpretation of the research as viable.

The report published in Science last year by researchers led by Felisa Wolfe-Simon of NASA's Astrobiology Institute said, the researchers had identified bacteria that can substitute arsenic for some of the phosphorous in their diet. (See: Discovery of arsenic eating bacterium opens up new vistas for extra terrestrial life exploration)

They said though the discovery was made on earth, the research showed possibilities of life extended beyond the major elements considered essential.

Six major elements have long been considered essential to sustain life - carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. Arsenic is toxic due to its chemical behaviour, however it is so similar to phosphorus that some organisms mistake it for phosphorus. 

However, once inside the body the element being different can disrupt the body's chemistry.