The Thermoproteota are prokaryotes that have been classified as a phylum of the domain Archaea. Initially, the Thermoproteota were thought to be sulfur-dependent extremophiles but recent studies have identified characteristic Thermoproteota environmental rRNA indicating the organisms may be the most abundant archaea in the marine environment. Originally, they were separated from the other archaea based on rRNA sequences; other physiological features, such as lack of histones, have supported this division, although some crenarchaea were found to have histones. Until 2005 all cultured Thermoproteota had been thermophilic or hyperthermophilic organisms, some of which have the ability to grow at up to 113 °C. These organisms stain Gram negative and are morphologically diverse, having rod, cocci, filamentous and oddly-shaped cells. Recent evidence shows that some members of the Thermoproteota are methanogens.
The Thermoprotei is a class of the Thermoproteota.
Mollicutes is a class of bacteria distinguished by the absence of a cell wall. The word "Mollicutes" is derived from the Latin mollis, and cutis. Individuals are very small, typically only 0.2–0.3 μm in size and have a very small genome size. They vary in form, although most have sterols that make the cell membrane somewhat more rigid. Many are able to move about through gliding, but members of the genus Spiroplasma are helical and move by twisting. The best-known genus in the Mollicutes is Mycoplasma. Colonies show the typical "fried-egg" appearance.
Acholeplasmataceae is a family of bacteria. It is the only family in the order Acholeplasmatales, placed in the class Mollicutes. The family comprises the genera Acholeplasma and Phytoplasma. Phytoplasma has the candidatus status, because members still could not be cultured.
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.
In the taxonomy of microorganisms, the Methanomicrobia are a class of the Euryarchaeota.
The Desulfurococcales is an order of the Thermoprotei, part of the kingdom Archaea. The order encompasses some genera which are all thermophilic, autotrophs which utilise chemical energy, typically by reducing sulfur compounds using hydrogen. Desulfurococcales cells are either regular or irregular coccus in shape, with forms of either discs or dishes. These cells can be single, in pairs, in short chains, or in aciniform formation.
In the taxonomy of microorganisms, the Methanomicrobiales are an order of the Methanomicrobia. Methanomicrobiales are strictly carbon dioxide reducing methanogens, using hydrogen or formate as the reducing agent. As seen from the phylogenetic tree based on 'The All-Species Living Tree' Project the family Methanomicrobiaceae is highly polyphyletic within the Methanomicrobiales.
Methanomicrobiaceae are a family of archaea in the order the Methanomicrobiales.
In taxonomy, Methanococcoides is a genus of the Methanosarcinaceae.
Acidilobus is a genus of archaea in the family Acidilobaceae.
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.
Halobaculum is a genus of the Halorubraceae.
Halorhabdus is a genus of halophilic archaea in the Haloarculaceae. With an extremely high salinity optimum of 27% NaCl, Halorhabdus has one of the highest reported salinity optima of any living organism.
Natrinema is a genus of the Natrialbaceae.
Natronorubrum is a genus in the family Halobacteriaceae.
Methanocalculus is a genus of the Methanomicrobiales, and is known to include methanogens.
In the taxonomy of microorganisms, Candidatus Methanoregula is a genus of the Methanomicrobiales. It was isolated from an acidic peat bog. It produces methane at the lowest pH of any known organism.
The Synergistota is a phylum of anaerobic bacteria that show Gram-negative staining and have rod/vibrioid cell shape. Although Synergistota have a diderm cell envelope, the genes for various proteins involved in lipopolysaccharides biosynthesis have not yet been detected in Synergistota, indicating that they may have an atypical outer cell envelope. The Synergistota inhabit a majority of anaerobic environments including animal gastrointestinal tracts, soil, oil wells, and wastewater treatment plants and they are also present in sites of human diseases such as cysts, abscesses, and areas of periodontal disease. Due to their presence at illness related sites, the Synergistota are suggested to be opportunistic pathogens but they can also be found in healthy individuals in the microbiome of the umbilicus and in normal vaginal flora. Species within this phylum have also been implicated in periodontal disease, gastrointestinal infections and soft tissue infections. Other species from this phylum have been identified as significant contributors in the degradation of sludge for production of biogas in anaerobic digesters and are potential candidates for use in renewable energy production through their production of hydrogen gas. All of the known Synergistota species and genera are presently part of a single class (Synergistia), order (Synergistiales), and family (Synergistaceae).
The Coriobacteriia are a class of Gram-positive bacteria within the Actinomycetota phylum. Species within this group are nonsporulating, strict or facultative anaerobes that are capable of thriving in a diverse set of ecological niches. Gordonibacter species are the only members capable of motility by means of flagella within the class. Several species within the Coriobacteriia class have been implicated with human diseases that range in severity. Atopobium, Olsenella, and Cryptobacterium species have responsible for human oral infections including periodontitis, halitosis, and other endodontic infections. Eggerthella species have been associated with severe blood bacteraemia and ulcerative colitis.
