Founded in flooded soils. The species within the genus Methanobacterium vary widely in length and filaments are common. Cell walls appear to be Gram positive, but are composed of pseudomurein rather than peptidoglycan. They are non-motile and flagella are absent. All species grow with H 2 and CO 2 as a substrate for methanogenesis.
Cells are mesophillic or thermophillic.
Methylamines, methyl sulfides, acetates, are not catabolized. They can use sulfur, sulfite, thiosulfate, or ammonium sulfide as sulfur sources and glutamine, ammonium, or urea as nitrogen sources. There are 12 species of genus Methanobacterium and they have been isolated from aneraobic digestors, sewage sludge, manure, groundwater, and formation water of oil-bearing rocks. There are several media available for the isolation of methanobacteria. Most of the media consist of yeast extract in combination with compounds such as xylose, tryptone, and glucose.