| Archaeoglobus | |
|---|---|
Scientific classification  | |
| Domain: | Archaea |
| Kingdom: | Euryarchaeota |
| Class: | Archaeoglobi |
| Order: | Archaeoglobales |
| Family: | Archaeoglobaceae |
| Genus: | Archaeoglobus Stetter 1988 |
| Type species | |
| Archaeoglobus fulgidus Stetter 1988 | |
| Species | |
| |
Archaeoglobus is a genus of the phylum Euryarchaeota. [1] Archaeoglobus can be found in high-temperature oil fields where they may contribute to oil field souring.
Archaeoglobus grow anaerobically at extremely high temperatures between 60 and 95 °C, with optimal growth at 83 °C (ssp. A. fulgidus VC-16). [2] They are sulfate-reducing archaea, coupling the reduction of sulfate to sulfide with the oxidation of many different organic carbon sources, including complex polymers.
A. lithotrophicus live chemolitho-autotrophically from hydrogen, sulfate and carbon dioxide. Also A. profundus grow lithotrophically, but while this species needs acetate and CO2 for biosynthesis they are heterotroph. [3]
The complete A. fulgidus genome sequence revealed the presence of a nearly complete set of genes for methanogenesis. The function of these genes in A. fulgidus remains unknown, while the lack of the enzyme methyl-CoM reductase does not allow for methanogenesis to occur by a mechanism similar to that found in other methanogens.
Archaeoglobus members are hyperthermophiles that can be found in hydrothermal vents, oil deposits, and hot springs. They can produce biofilm when subjected to environmental stresses such as extreme pH or temperature, high concentrations of metal, or the addition of antibiotics, xenobiotics, or oxygen. These archaeons are known to cause the corrosion of iron and steel in oil and gas processing systems by producing iron sulphide. Their biofilms, however, may have industrial or research applications in the form of detoxifying metal contaminated samples or to gather metals in an economically recoverable form.
The Archaeoglobus fulgidus genome is a circular chromosome roughly half the size of E. coli at 2,178,000 base pairs. Although this is bacteria archaeoglobus can grow to the size of a quarter if fed properly. A quarter of the genome encodes preserved proteins whose functions are not yet determined, but are expressed in other archaeons such as Methanococcus jannaschii . Another quarter encodes proteins unique to the archaeal domain. One observation about the genome is that there are many gene duplications and the duplicated proteins are not identical. This suggests metabolic differentiation specifically with respect to the decomposing and recycling carbon pathways through scavenged fatty acids. The duplicated genes also gives the genome a larger genome size than its fellow archaeon M. jannaschii. It is also noted that Archaeoglobus contained no inteins in coding regions where M. jannaschii had 18.
Comparative genomic studies on archaeal genomes provide evidence that members of the genus Archaeoglobus are the closest relatives of methanogenic archaea. This is supported by the presence of 10 conserved signature proteins that are uniquely found in all methanogens and Archaeoglobus. Additionally, 18 proteins which are uniquely found in members of Thermococci, Archaeoglobus and methanogens have been identified, suggesting that these three groups of Archaea may have shared a common relative exclusive of other Archaea. However, the possibility that the shared presence of these signature proteins in these archaeal lineages is due to lateral gene transfer cannot be excluded. [4]
Archaeoglobus species utilize their environment by acting as scavengers with many potential carbon sources. They can obtain carbon from fatty acids, the degradation of amino acids, aldehydes, organic acids, and possibly CO as well. Higher temperatures (approx. 83 °C) are ideal growth temperatures for Archaeoglobus, although a biofilm environment provides some environmental elasticity. Biofilm is composed of polysaccharides, proteins, and metals.
Cells protected by biofilm are difficult to destroy using conventional anti-microbial therapy, which gives them medicinal possibilities. [2]
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) [5] and National Center for Biotechnology Information (NCBI). [1]
| 16S rRNA based LTP_06_2022 [6] [7] [8] | 53 marker proteins based GTDB 08-RS214 [9] [10] [11] | ||||||||||||||||||||||||||||||||||||||||||||||||
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Methanogens are anaerobic archaea that produce methane as a byproduct of their energy metabolism, i.e., catabolism. Methane production, or methanogenesis, is the only biochemical pathway for ATP generation in methanogens. All known methanogens belong exclusively to the domain Archaea, although some bacteria, plants, and animal cells are also known to produce methane. However, the biochemical pathway for methane production in these organisms differs from that in methanogens and does not contribute to ATP formation. Methanogens belong to various phyla within the domain Archaea. Previous studies placed all known methanogens into the superphylum Euryarchaeota. However, recent phylogenomic data have led to their reclassification into several different phyla. Methanogens are common in various anoxic environments, such as marine and freshwater sediments, wetlands, the digestive tracts of animals, wastewater treatment plants, rice paddy soil, and landfills. While some methanogens are extremophiles, such as Methanopyrus kandleri, which grows between 84 and 110°C, or Methanonatronarchaeum thermophilum, which grows at a pH range of 8.2 to 10.2 and a Na+ concentration of 3 to 4.8 M, most of the isolates are mesophilic and grow around neutral pH.
Archaeoglobaceae are a family of the Archaeoglobales. All known genera within the Archaeoglobaceae are hyperthermophilic and can be found near undersea hydrothermal vents. Archaeoglobaceae are the only family in the order Archaeoglobales, which is the only order in the class Archaeoglobi.
Ferroglobus is a genus of the Archaeoglobaceae.
Methanopyrus is a genus of methanogen, with a single described species, Methanopyrus kandleri. It is a rod-shaped hyperthermophile, discovered on the wall of a black smoker from the Gulf of California at a depth of 2,000 m, at temperatures of 84–110 °C. Strain 116 was discovered in black smoker fluid of the Kairei hydrothermal field; it can survive and reproduce at 122 °C. M. kandleri also requires a high ionic concentration in order for growth and cellular activity. Due to the species' high resilience and extreme environment, M. kandleri is also classified as an extremophile. It lives in a hydrogen–carbon dioxide rich environment, and like other methanogens reduces the latter to methane. It is placed among the Euryarchaeota, in its own class.
Sulfolobus is a genus of microorganism in the family Sulfolobaceae. It belongs to the archaea domain.
Geoglobus is a hyperthermophilic member of the Archaeoglobaceae within the Euryarchaeota. It consists of two species, the first, G. ahangari, isolated from the Guaymas Basin hydrothermal system located deep within the Gulf of California. As a hyperthermophile, it grows best at a temperature of 88 °C and cannot grow at temperatures below 65 °C or above 90 °C. It possess an S-layer cell wall and a single flagellum. G. ahangari is an anaerobe, using poorly soluble ferric iron (Fe3+) as a terminal electron acceptor. It can grow either autotrophically using hydrogen gas (H2) or heterotrophically using a large number of organic compounds, including several types of fatty acids, as energy sources. G. ahangari was the first archaeon isolated capable of using hydrogen gas coupled to iron reduction as an energy source and the first anaerobe isolated capable of using long-chain fatty acids as an energy source.
Methanosarcina is a genus of euryarchaeote archaea that produce methane. These single-celled organisms are known as anaerobic methanogens that produce methane using all three metabolic pathways for methanogenesis. They live in diverse environments where they can remain safe from the effects of oxygen, whether on the earth's surface, in groundwater, in deep sea vents, and in animal digestive tracts. Methanosarcina grow in colonies.
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.
Sulfolobaceae are a family of the Sulfolobales belonging to the domain Archaea. The family consists of several genera adapted to survive environmental niches with extreme temperature and low pH conditions.
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.
Pyrobaculum is a genus of the Thermoproteaceae.
In taxonomy, Vulcanisaeta is a genus of the Thermoproteaceae.
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.
Archaea is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotic. Archaea were initially classified as bacteria, receiving the name archaebacteria, but this term has fallen out of use.
Methanocaldococcus jannaschii is a thermophilic methanogenic archaean in the class Methanococci. It was the first archaeon, and third organism, to have its complete genome sequenced. The sequencing identified many genes unique to the archaea. Many of the synthesis pathways for methanogenic cofactors were worked out biochemically in this organism, as were several other archaeal-specific metabolic pathways.
The archaellum is a unique structure on the cell surface of many archaea that allows for swimming motility. The archaellum consists of a rigid helical filament that is attached to the cell membrane by a molecular motor. This molecular motor – composed of cytosolic, membrane, and pseudo-periplasmic proteins – is responsible for the assembly of the filament and, once assembled, for its rotation. The rotation of the filament propels archaeal cells in liquid medium, in a manner similar to the propeller of a boat. The bacterial analog of the archaellum is the flagellum, which is also responsible for their swimming motility and can also be compared to a rotating corkscrew. Although the movement of archaella and flagella is sometimes described as "whip-like", this is incorrect, as only cilia from Eukaryotes move in this manner. Indeed, even "flagellum" is a misnomer, as bacterial flagella also work as propeller-like structures.
Archaeoglobus profundus is a sulphate-reducing archaea. Archaeoglobus can be found in high-temperature oil fields where it may contribute to oil field souring. A. profundus grows lithotrophically, and while it needs acetate and CO2 for biosynthesis it is heterotrophic.
Methanococcoides burtonii is a methylotrophic methanogenic archaeon first isolated from Ace Lake, Antarctica. Its type strain is DSM 6242.
Methanococcus maripaludis is a species of methanogenic archaea found in marine environments, predominantly salt marshes. M. maripaludis is a non-pathogenic, gram-negative, weakly motile, non-spore-forming, and strictly anaerobic mesophile. It is classified as a chemolithoautotroph. This archaeon has a pleomorphic coccoid-rod shape of 1.2 by 1.6 μm, in average size, and has many unique metabolic processes that aid in survival. M. maripaludis also has a sequenced genome consisting of around 1.7 Mbp with over 1,700 identified protein-coding genes. In ideal conditions, M. maripaludis grows quickly and can double every two hours.
Methanocaldococcussp. FS406-22 is an archaea in the genus Methanocaldococcus. It is an anaerobic, piezophilic, diazotrophic, hyperthermophilic marine archaeon. This strain is notable for fixing nitrogen at the highest known temperature of nitrogen fixers recorded to date. The 16S rRNA gene of Methanocaldococcus sp. FS406-22, is almost 100% similar to that of Methanocaldococcus jannaschii, a non-nitrogen fixer.