methanogen

noun

me·​than·​o·​gen mə-ˈtha-nə-ˌjen 

plural methanogens

: any of various anaerobic archaea (as of the families Methanobacteriaceae and Methanosarcinaceae of the taxon Euryarchaeota) that produce methane as a by-product of energy metabolism, are found in various chiefly anoxic environments (such as aquatic sediments, rice paddies, landfills, hydrothermal vents, and the digestive tract of ruminants, humans, and termites), and typically utilize hydrogen and carbon dioxide as a substrate for energy production but may use other substrates (such as acetate or methylamine)

Some microbes called methanogens, for instance, exude as waste the powerful greenhouse gas methane.

—Charles Petit

… these reactions are part of the pathway that reduces CO₂ to methane, the central pathway for energy metabolism in methanogens.

—Ludmila Christoserdova et al.

Examples of methanogen in a Sentence

Recent Examples on the Web

Rethinking Diets for Different Bodies While the participants were all relatively healthy, the researchers are curious to see how methanogen activity might impact people with different health conditions. —Jenny Lehmann, Discover Magazine, 13 June 2025

One pathway for inoculating the moon would be to first introduce methanogens, a simple microbe that can convert hydrogen and carbon dioxide and produce biomass. —Joshua Rapp Learn, Smithsonian Magazine, 28 May 2025

Liquid water is essential for supporting all life, even the hardy methanogens. —Paul Sutter, Space.com, 1 Jan. 2025

Scientists have already found methanogens in all of these environments on Earth, but that's not precise enough. —Paul Sutter, Space.com, 1 Jan. 2025

Some of these nourish the cow, while others are food for methane-producing microbes called methanogens. —Bob Holmes, Discover Magazine, 29 June 2024

The researchers showed a correlation between the presence of the methanogen Methanobrevibacter and the bacterium Prevotella. —Jeffrey Marlow, Discover Magazine, 28 Feb. 2017

Word History

Etymology

methane + -o- + -gen, after methanogenic

First Known Use

1976, in the meaning defined above

Rhymes for methanogen

• andropogon
• dogon
• noggin
• toboggan

Medical Definition

methanogen

noun

me·​than·​o·​gen mə-ˈthan-ə-ˌjen 

: any of various anaerobic archaea (as of the families Methanobacteriaceae and Methanosarcinaceae of the taxon Euryarchaeota) that produce methane as a by-product of energy metabolism, are found in various chiefly anoxic environments (as aquatic sediments, rice paddies, landfills, hydrothermal vents, and the digestive tract of ruminants, humans, and termites), and typically utilize hydrogen and carbon dioxide as a substrate for energy production but may use other substrates (as acetate or methylamine)