Arsenic Bacteria Discovered
Researchers have found several bacteria who "breathe" arsenic, similar to humans who breathe oxygen and release carbon dioxide, these organisms inhale arsenic III and exhale arsenic V. Studies revealed that arsenic is also used by the bacteria to photosynthesize.
More than a mere biological oddity, the discovery adds weight to Oremland's theory that the bacteria's ability evolved billions of years ago, when the first life was just getting started on earth.
At the time, the planet's oceans were devoid of oxygen, but hydrothermal vents spewed elements such as sulfur, iron and arsenic into the water column.
In this ancient stew, arsenic may have been an important nutrient to life.
As the life-forms found they could make a living off of these odd bedfellows, one of the first forms of photosynthesis was born.
Modern photosynthesis is thought to have evolved between 2.3 and 2.7 billion years ago. The arsenic-based form may be much, much older ...
