July 13, 2009
Iron and manganese used to convert methane
U.S. scientists say they have discovered marine microorganisms use manganese and iron to convert methane into carbon dioxide.
The Pennsylvania State University researchers said their finding is important because carbon dioxide can produce compounds that sequester carbon in the ocean, reducing the amount of CO2 in the Earth's atmosphere. That process had previously been thought to be dependent on compounds containing sulfur.
In the empty space above the sediment, the researchers placed methane gas containing a non-radioactive carbon-13 isotope and later measured the amount of any carbon dioxide produced by the samples.
They found the sulfur compound produced the most carbon dioxide, but samples with iron and manganese also produced some of the gas.
People had speculated that iron and manganese could be used, but no one had shown that it occurred by incubating live organisms, said Beal.
The study appears in the journal Science.