By Sid Perkins
Microbiologists have discovered bacteria that can produce oxygen by breaking down nitrite compounds, a novel metabolic trick that allows the bacteria to consume methane found in oxygen-poor sediments.
Previously, researchers knew of three other biological pathways that could produce oxygen. In photosynthesis, microbes or plants containing chlorophyll grow by gleaning energy from the sun, releasing oxygen as a waste product. In the two other schemes, cells generate oxygen — typically for their own internal use — by using enzymes to break down oxygen-containing substances such as chlorates, says Katharina Ettwig, a microbiologist at Radboud University Nijmegen in the Netherlands.
The newly discovered pathway opens up new possibilities for understanding how and where oxygen can be created, Ettwig and her colleagues report in the March 25 Nature.
“This is a seminal discovery,” says Ronald Oremland, a geomicrobiologist with the U.S. Geological Survey in Menlo Park, Calif., who was not involved with the work. The findings, he says, could even have implications for oxygen creation elsewhere in the solar system.