Researchers from the Research Group for Deep-Sea Ecology and Technology of the Helmholtz Association and the Max Planck Society discovered microbial communities thriving on the hydrocarbon butane without the help of molecular oxygen. The microbial consortia, obtained from hydrothermally heated sediments in Guaymas Basin, Gulf of California, use unprecedented biochemistry to feed on butane.
Natural gas is often released at the seafloor surface. In the upper sediment layers methane is formed by methanogenic archaea. Economically more valuable gas reservoirs are however situated in deeper layers of the seafloor. Here gas forms in purely chemical reactions from geothermally heated biomass of plant, animal and microbial origin. Along with methane, the thermogenic (thermally generated) gas contains other hydrocarbons such as propane and butane.
As anyone who has lit a gas stove, a lighter or started a gas powered car knows, burning gas requires oxygen. Also many microorganisms eat hydrocarbon gases by using oxygen, for instance in well-oxygenated top sediment layers. When the oxygen is used up, other microorganisms take over. Distinct microorganisms specialized on the anaerobic oxidation of different hydrocarbons.
For more information about how microorganisms consume natural gas without molecular oxygen read the press release of the Max Planck Institute for Marine Microbiology