Euryarchaeota is a kingdom of archaea. Euryarchaeota are highly diverse and include methanogens, which produce methane and are often found in intestines; halobacteria, which survive extreme concentrations of salt; and some extremely thermophilic aerobes and anaerobes, which generally live at temperatures between 41 and 122 °C. They are separated from the other archaeans based mainly on rRNA sequences and their unique DNA polymerase. The only validly published name for this group under the Prokaryotic Code is Methanobacteriati.
Chrysiogenaceae is a family of bacteria.
The Thermoprotei is a class of the Thermoproteota.
Atopobium is a genus of Actinomycetota, in the family Coriobacteriaceae. Atopobium species are anaerobic, Gram-positive rod-shaped or elliptical bacteria found as single elements or in pairs or short chains.
Methanococcus is a genus of coccoid methanogens of the family Methanococcaceae. They are all mesophiles, except the thermophilic M. thermolithotrophicus and the hyperthermophilic M. jannaschii. The latter was discovered at the base of a “white smoker” chimney at 21°N on the East Pacific Rise and it was the first archaeal genome to be completely sequenced, revealing many novel and eukaryote-like elements.
Methanobacteriales is an order of archaeans in the class Methanobacteria. Species within this order differ from other methanogens in that they can use fewer catabolic substrates and have distinct morphological characteristics, lipid compositions, and RNA sequences. Their cell walls are composed of pseudomurein. Most species are Gram-positive with rod-shaped bodies and some can form long filaments. Most of them use formate to reduce carbon dioxide, but those of the genus Methanosphaera use hydrogen to reduce methanol to methane.
In taxonomy, the Methanococcales are an order of the Methanococci.
In taxonomy, the Methanocorpusculaceae are a family of microbes within the order Methanomicrobiales. It contains exactly one genus, Methanocorpusculum. The species within Methanocorpusculum were first isolated from anaerobic digesters and anaerobic wastewater treatment plants. In the wild, they prefer freshwater environments. Unlike many other methanogenic archaea, they do not require high temperatures or extreme salt concentrations to live and grow.
In taxonomy, the Methanosarcinaceae are a family of the Methanosarcinales.
In taxonomy, Methanococcoides is a genus of the Methanosarcinaceae.
Methanocaldococcus formerly known as Methanococcus is a genus of coccoid methanogen archaea. They are all mesophiles, except the thermophilic M. thermolithotrophicus and the hyperthermophilic M. jannaschii. The latter was discovered at the base of a “white smoker” chimney at 21°N on the East Pacific Rise and it was the first archaean genome to be completely sequenced, revealing many novel and eukaryote-like elements.
In taxonomy, Methanohalophilus is a genus of the Methanosarcinaceae.
In taxonomy, Methanomethylovorans is a genus of microorganisms with the family Methanosarcinaceae. This genus was first described in 1999. The species within it generally live in freshwater environments, including rice paddies, freshwater sediments and contaminated soil. They produce methane from methanol, methylamines, dimethyl sulfide and methanethiol. With the exception of M. thermophila, which has an optimal growth temperature of 50 °C, these species are mesophiles and do not tend to grow at temperatures above 40 °C.
Methanobacterium is a genus of the Methanobacteria class in the Archaea kingdom, which produce methane as a metabolic byproduct. Despite the name, this genus belongs not to the bacterial domain but the archaeal domain. Methanobacterium are nonmotile and live without oxygen, which is toxic to them, and they only inhabit anoxic environments.
Methanosphaera is a genus of microbes within the family Methanobacteriaceae. It was distinguished from other genera within Methanobacteriaceae in 1985 on the basis of the oligonucleotide sequence of its 16S RNA. Like other archaea within Methanobacteriaceae, those of Methanosphaera are methanogens, but while most use formate to reduce carbon dioxide, those of Methanosphaera use hydrogen to reduce methanol to methane.
Methanothermobacter is a genus of archaeans in the family Methanobacteriaceae. The species within this genus are thermophilic and grow best at temperatures between 55 °C and 65 °C. They are methanogens; they use carbon dioxide and hydrogen as substrates to produce methane for energy.
In taxonomy, Methanocorpusculum is a genus of microbes within the family Methanocorpusculaceae. The species within Methanocorpusculum were first isolated from biodisgester wastewater and activated sludge from anaerobic digestors. In nature, they live in freshwater environments. Unlike most other methanogenic archaea, they do not require high temperatures or extreme salt concentrations to live and grow.
In taxonomy, Methanofollis is a genus of the Methanomicrobiaceae.
Methanocalculus is a genus of the Methanomicrobiales, and is known to include methanogens.
Methanobrevibacter smithii is the predominant methanogenic archaeon in the microbiota of the human gut. M. smithii has a coccobacillus shape. It plays an important role in the efficient digestion of polysaccharides (complex sugars) by consuming the end products of bacterial fermentation (H2, CO2, acetate, and formate). M. smithii is a hydrogenotrophic methanogen that utilizes hydrogen by combining it with carbon dioxide to form methane. The removal of hydrogen by M. smithii is thought to allow an increase in the extraction of energy from nutrients by shifting bacterial fermentation to more oxidized end products.
