Methane Production by bacteriaBy :

amira shaalan

Methane Oxidizing and Producing Bacteria• Methane is a chemical compound that consists of a

carbon atom to which are bound four hydrogen atoms. • These bacteria are known as methane oxidizing

bacteria.• 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.

• Methane is described as being a greenhouse gas, which means it can warm the surface atmosphere.

Methanogenes • 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.

Methanogenes • 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 house the enzymes and other biochemical machinery needed to deal with the se of methane as an energy source.

Oxidation of methane• The oxidation of methane by bacteria requires

oxygen. The end result is the production of carbon dioxide and water. Methane oxidation is restricted to prokaryotes. Eukaryotic microorganisms such as algae and fungi do not oxidize methane.

Production of methane• Methanogenic bacteria (anaerobic) are widespread in

nature, and are found in mud, sewage, and sludge and in the rumen of sheep and cattle. Some methanogenic bacteria have adapted to live in extreme

• environments.(i.e. hot springs and thermal vents in the ocean)

• the methane-producing bacteria occupy a central role in regulating the anaerobic breakdown (fermentation) of food.

• The bacteria remove hydrogen gas through the se of the gas in the reduction of carbon dioxide to form methane. By producing methane, the concentration of hydrogen is kept at a low level that allows other bacterial species to grow. This microbial diversity makes fermentation more efficient.

Economic importance• The bacterial production of methane is

of economic importance. "Biogas" obtained from digesters can be a commercial and domestic energy source, although more economic sources of energy currently limit this use.