Methane is a chemical compound that consists of a carbon atom to which are bound four hydrogen atoms. The gas is a major constituent of oxygen-free mud and water, marshes, the rumen of cattle and other animals, and the intestinal tract of mammals. In oxygen-free (anaerobic) environments, methane can be produced by a type of bacteria known as methanogenic bacteria. Methane can also be used as an energy source by other bacteria that grow in the presence of oxygen (aerobic bacteria), which break down the compound into carbon dioxide and water. These bacteria are known as methane oxidizing bacteria.

Bacteria from a number of genera are able to oxidize methane. These include Methylosinus, Methylocystis, Methanomonas, Methylomonas, Methanobacter, and Methylococcus. A characteristic feature of methane-oxidizing bacteria is the presence of an extensive system of membranes inside the bacterial cell. The membranes...