(redirected from Biomethanation)

Methanogenesis (bacteria)

The microbial formation of methane, which is confined to anaerobic habitats where occurs the production of hydrogen, carbon dioxide, formic acid, methanol, methylamines, or acetate—the major substrates used by methanogenic microbes (methanogens). In fresh-water or marine sediments, in the intestinal tracts of animals, or in habitats engineered by humans such as sewage sludge or biomass digesters, these substrates are the products of anaerobic bacterial metabolism. Methanogens are terminal organisms in the anaerobic microbial food chain—the final product, methane, being poorly soluble, anaerobically inert, and not in equilibrium with the reaction which produces it.

Two highly specialized digestive organs, the rumen and the cecum, have been evolved by herbivores to delay the passage of cellulose fibers so that microbial fermentation may be complete. In these organs, large quantities of methane are produced from hydrogen and carbon dioxide or formic acid by methanogens. From the rumen, an average cow may belch 26 gallons (100 liters) of methane per day.

Methanogens are the only living organisms that produce methane as a way of life. The biochemistry of their metabolism is unique and definitively delineates the group. Two reductive biochemical strategies are employed: an eight-electron reduction of carbon dioxide to methane or a two-electron reduction of a methyl group to methane. All methogens form methane by reducing a methyl group. The major energy-yielding reactions used by methanogens utilize substrates such as hydrogen, formic acid, methanol, acetic acid, and methylamine. Dimethyl sulfide, carbon monoxide, and alcohols such as ethanol and propanol are substrates that are used less frequently. See Archaebacteria, Bacterial physiology and metabolism

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.


The biosynthesis of the hydrocarbon methane; common in certain bacteria. Also known as bacterial methanogenesis.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
ENPNewswire-August 15, 2019--Southern California Gas Company - SoCalGas and Electrochaea Announce Commissioning of New Biomethanation Reactor System Pilot Project
International Resource News-August 14, 2019--Southern California Gas Co and Electrochaea install biomethanation reactor system in Colorado
Enhanced Biomethanation in Co-Digestion of Cassava Pulp and Pig Manure Using a Two-PhaseAnaerobic System.
Among the WtE technologies allowed under the guidelines are gasification, pyrolysis, bioreactor, biomethanation, hydrolysis, pyrolytic gasification, plasma and other thermal processes.
Ferry, "Fundamentals of methanogenic pathways that are key to the biomethanation of complex biomass," Current Opinion in Biotechnology, vol.
Various researchers have investigated the potential of food waste as a substrate for biomethanation. Viturtia et al.
" They are neither doing biomethanation for wet waste nor producing Refuse- Derived Fuel.
Praj will provide key technologies for fermentation, distillation, and wastewater treatment including biomethanation followed by biocomposting.
This could theoretically produce 745m standard cubic feet of biogas through biomethanation according to estimates derived from a study by Veolia.