Large amounts of methane are produced in marine sediments[2] but are then consumed before contacting aerobic waters or the atmosphere. Although no organism that can consume methane anaerobically has ever been isolated, biogeochemical evidence indicates that the overall process involves a transfer of electrons from methane to sulphate and is probably mediated by several organisms, including a methanogen (operating in reverse) and a sulfate-reducer (using an unknown intermediate substrate).
Organisms placed within the order can be found in freshwater, saltwater, salt-rich sediments, laboratory digestors, and animal digestive systems. Most cells have cell walls that lack peptidoglycan and pseudomurein. They are strictly anaerobic and survive by producing methane. Some species use acetate as a substrate and others use methyl compounds, such as methyl amines and methyl sulfates.[3]
^Kendall, Melissa M.; David R. Boone (2006-10-10). "12". In Stanley Falkow; Eugene Rosenberg; Karl-Heinz Schleifer; Erko Stackebrandt (eds.). The Prokaryotes. Vol. 3. Springer Science & Business Media. p. 244. doi:10.1007/0-387-30743-5_12. ISBN0387254935. Retrieved 2016-08-27.
Grant WD; Kamekura M; McGenity TJ; Ventosa A (2001). "Class III. Halobacteria class. nov.". In DR Boone; RW Castenholz (eds.). Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria (2nd ed.). New York: Springer Verlag. pp. 169. ISBN978-0-387-98771-2.
Garrity GM; Bell JA; Lilburn TG (2004). "Taxonomic Outline of the Prokaryotes". Bergey's Manual of Systematic Bacteriology, release 4.0 (2nd ed.). New York: Springer Verlag. doi:10.1007/bergeysoutline200310 (inactive 31 January 2024).{{cite book}}: CS1 maint: DOI inactive as of January 2024 (link)Version 5.0.
