Methanosarcina barkeri fusaro
Methanosarcina barkeri fusaro is a methanogenic Archaebacterium. Methanogens are organisms that make methane via a unique metabolic pathway with unique enzymes and cofactors. All of the methanogens are lithotrophs that can make their own energy only by methanogenesis. Most methanogens can make methane from carbon dioxide and hydrogen gas. Some methanogens can use other 1-carbon compounds, such as carbon monoxide or formic acid, and a few others can use acetate and methylamines. Enzymes in the metabolic pathway are very oxygen sensitive. Bacteria in the Methanosarcina family are slow developers and are sensitive to sudden change in physical and chemical conditions, but they are capable of growth in a variety of substrates. This metabolic diversity makes them an especially attractive target for genetic analysis.

The fusaro strain or M. barkeri was isolated from mud samples taken from the freshwater lake Lago del Fusaro near Naples (Italy). It has also been reported that Methanosarcina barkeri fusaro lives in the rumen of cattle. The rumen is an organ where microbial populations collaborate to digest cellulose and other polysaccharides, producing carbon dioxide, methane and organic acids. There is no oxygen in the rumen and these organisms are very oxygen sensitive. Therefore, Methanosarcina barkeri fusaro is an anaerobe, extreme anaerobe, if you will. The ecruate consists of methane, up to 35% and 65% carbon dioxide. Average daily production of gas from a cow is about 100-150 L a day. A well-fed dairy cow can generate as much as 500 L of gas daily. Methane gas from cows could be a major contributor to the problem with the ozone layer. -- Jessica Brill