39-479: The Thermotogota are a phylum of the domain Bacteria . The phylum contains a single class, Thermotogae . The phylum Thermotogota is composed of Gram-negative staining, anaerobic , and mostly thermophilic and hyperthermophilic bacteria. The name of this phylum is derived from the existence of many of these organisms at high temperatures along with the characteristic sheath structure, or "toga", surrounding
78-578: A "toga". The members of the phylum stain Gram-negative as they possess a thin peptidoglycan in between two lipid bilayers, albeit both peculiar. The peptidoglycan is unusual as the crosslink is not only meso-diaminopimelate as occurs in Pseudomonadota , but D-lysine. The species are anaerobes with varying degrees of oxygen tolerance. They are capable of reducing elemental sulphur (S 0 ) to hydrogen sulphide. Whether thermophily
117-556: A certain degree of morphological or developmental similarity (the phenetic definition), or a group of organisms with a certain degree of evolutionary relatedness (the phylogenetic definition). Attempting to define a level of the Linnean hierarchy without referring to (evolutionary) relatedness is unsatisfactory, but a phenetic definition is useful when addressing questions of a morphological nature—such as how successful different body plans were. The most important objective measure in
156-407: A character unique to a sub-set of the crown group. Furthermore, organisms in the stem group of a phylum can possess the "body plan" of the phylum without all the characteristics necessary to fall within it. This weakens the idea that each of the phyla represents a distinct body plan. A classification using this definition may be strongly affected by the chance survival of rare groups, which can make
195-402: A group ("a self-contained unity"): "perhaps such a real and completely self-contained unity is the aggregate of all species which have gradually evolved from one and the same common original form, as, for example, all vertebrates. We name this aggregate [a] Stamm [i.e., stock] ( Phylon )." In plant taxonomy , August W. Eichler (1883) classified plants into five groups named divisions,
234-602: A group containing Viridiplantae and the algal Rhodophyta and Glaucophyta divisions. The definition and classification of plants at the division level also varies from source to source, and has changed progressively in recent years. Thus some sources place horsetails in division Arthrophyta and ferns in division Monilophyta, while others place them both in Monilophyta, as shown below. The division Pinophyta may be used for all gymnosperms (i.e. including cycads, ginkgos and gnetophytes), or for conifers alone as below. Since
273-547: A non-essential consequence to thermophily and not the driver towards thermophily. The paper and the chapter in Bergey's manual were authored by several authors including the microbiologists Karl Stetter and Carl Woese . The Neo-Latin feminine name "thermotoga" means "the hot outer garment", being a combination of the Greek noun θέρμη ( therme , heat) or more correctly the adjective θερμός, ή, όν ( thermos, e, on , hot) and
312-430: A number of its subgroups. Many of these CSIs in important housekeeping proteins such as Pol1 , RecA , and TrpRS , and ribosomal proteins L4, L7/L12, S8, S9, etc. are uniquely present in different sequenced Thermotogota species providing novel molecular markers for this phylum. These studies also identified CSIs specific for each order and each family. These indels are the premise for the current taxonomic organization of
351-400: A phylum based on body plan has been proposed by paleontologists Graham Budd and Sören Jensen (as Haeckel had done a century earlier). The definition was posited because extinct organisms are hardest to classify: they can be offshoots that diverged from a phylum's line before the characters that define the modern phylum were all acquired. By Budd and Jensen's definition, a phylum is defined by
390-471: A phylum much more diverse than it would be otherwise. Total numbers are estimates; figures from different authors vary wildly, not least because some are based on described species, some on extrapolations to numbers of undescribed species. For instance, around 25,000–27,000 species of nematodes have been described, while published estimates of the total number of nematode species include 10,000–20,000; 500,000; 10 million; and 100 million. The kingdom Plantae
429-706: A phylum, other phylum-level ranks appear, such as the case of Bacillariophyta (diatoms) within Ochrophyta . These differences became irrelevant after the adoption of a cladistic approach by the ISP, where taxonomic ranks are excluded from the classifications after being considered superfluous and unstable. Many authors prefer this usage, which lead to the Chromista-Protozoa scheme becoming obsolete. Currently there are 40 bacterial phyla (not including " Cyanobacteria ") that have been validly published according to
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#1732780756596468-435: A possible biotechnological source for production of energy alternative to fossil fuels. Until recently, no biochemical or molecular markers were known that could distinguish the species from the phylum Thermotogota from all other bacteria. However, a recent comparative genomic study has identified large numbers of conserved signature indels (CSIs) in important proteins that are specific for either all Thermotogota species or
507-401: A set of characters shared by all its living representatives. This approach brings some small problems—for instance, ancestral characters common to most members of a phylum may have been lost by some members. Also, this definition is based on an arbitrary point of time: the present. However, as it is character based, it is easy to apply to the fossil record. A greater problem is that it relies on
546-564: A single class (Thermotogae), four orders ( Thermotogales , Kosmotogales , Petrotogales , and Mesoaciditogales ) and five families (Thermatogaceae, Fervidobacteriaceae, Kosmotogaceae, Petrotogaceae, and Mesoaciditogaceae). It contains a total of 15 genera and 52 species. In the 16S rRNA trees, the Thermotogota have been observed to branch with the Aquificota (another phylum comprising hyperthermophilic organisms) in close proximity to
585-401: A subjective decision about which groups of organisms should be considered as phyla. The approach is useful because it makes it easy to classify extinct organisms as " stem groups " to the phyla with which they bear the most resemblance, based only on the taxonomically important similarities. However, proving that a fossil belongs to the crown group of a phylum is difficult, as it must display
624-424: A term that remains in use today for groups of plants, algae and fungi. The definitions of zoological phyla have changed from their origins in the six Linnaean classes and the four embranchements of Georges Cuvier . Informally, phyla can be thought of as groupings of organisms based on general specialization of body plan . At its most basic, a phylum can be defined in two ways: as a group of organisms with
663-474: Is a paraphyletic taxon, which is less acceptable to present-day biologists than in the past. Proposals have been made to divide it among several new kingdoms, such as Protozoa and Chromista in the Cavalier-Smith system . Protist taxonomy has long been unstable, with different approaches and definitions resulting in many competing classification schemes. Many of the phyla listed below are used by
702-410: Is an innovation of the lineage or an ancestral trait is unclear and cannot be determined. The genome of Thermotoga maritima was sequenced in 1999, revealing several genes of archaeal origin, possibly allowing its thermophilic adaptation. The CG (cytosine-guanine) content of T. maritima is 46.2%; most thermophiles in fact have high CG content; this has led to the speculation that CG content may be
741-405: Is defined in various ways by different biologists (see Current definitions of Plantae ). All definitions include the living embryophytes (land plants), to which may be added the two green algae divisions, Chlorophyta and Charophyta , to form the clade Viridiplantae . The table below follows the influential (though contentious) Cavalier-Smith system in equating "Plantae" with Archaeplastida ,
780-481: Is generally included in kingdom Fungi, though its exact relations remain uncertain, and it is considered a protozoan by the International Society of Protistologists (see Protista , below). Molecular analysis of Zygomycota has found it to be polyphyletic (its members do not share an immediate ancestor), which is considered undesirable by many biologists. Accordingly, there is a proposal to abolish
819-532: Is not as high as suggested in earlier studies. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI) Phylum In biology , a phylum ( / ˈ f aɪ l əm / ; pl. : phyla ) is a level of classification or taxonomic rank below kingdom and above class . Traditionally, in botany
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#1732780756596858-573: The Bacteriological Code Currently there are 2 phyla that have been validly published according to the Bacteriological Code Other phyla that have been proposed, but not validly named, include: Thermotoga Thermotoga is a genus of the phylum Thermotogota . Members of Thermotoga are hyperthermophilic bacteria whose cell is wrapped in a unique sheath-like outer membrane, called
897-565: The Catalogue of Life , and correspond to the Protozoa-Chromista scheme, with updates from the latest (2022) publication by Cavalier-Smith . Other phyla are used commonly by other authors, and are adapted from the system used by the International Society of Protistologists (ISP). Some of the descriptions are based on the 2019 revision of eukaryotes by the ISP. The number of protist phyla varies greatly from one classification to
936-915: The CSI and a ADP/ATP molecule. It is thought that this network helps to maintain ADP/ATP binding to the SecA protein at high temperatures, contributing to the overall thermostable phenotype some Thermotogales species. Athalassotoga Mesoaciditoga Mesotoga Kosmotoga Marinitoga Tepiditoga Oceanotoga Geotoga Defluviitoga Petrotoga Thermotoga Pseudothermotoga Fervidobacterium Thermosipho Athalassotoga Mesoaciditoga Mesotoga Kosmotoga Marinitoga Tepiditoga Oceanotoga Geotoga Defluviitoga Petrotoga Thermotoga Pseudothermotoga Fervidobacterium Thermosipho This phylum presently consists of
975-647: The Latin feminine noun toga (the Roman outer garment). The precise relation of the Thermotogota to other phyla is debated ( v. bacterial phyla ): several studies have found it to be deep-branching (in Bergey's manual it appeared in fact in "Volume I: The Archaea and the deeply branching and phototrophic Bacteria"), while other have found Firmicutes to be deep-branching with Thermotogota clustering away from
1014-468: The Thermotogota, and are strongly supported by phylogenomic analyses. Additional CSIs have also been found that are specific for Thermotoga , Pseudothermotoga , Fervidobacterium , and Thermosipho . These CSIs are specific for all species within each respective genus, and absent in all other bacteria, thus are specific markers. A clade consisting of the deep-branching species Petrotoga mobilis , Kosmotoga olearia , and Thermotogales bacterium mesG1
1053-497: The Zygomycota phylum. Its members would be divided between phylum Glomeromycota and four new subphyla incertae sedis (of uncertain placement): Entomophthoromycotina , Kickxellomycotina , Mucoromycotina , and Zoopagomycotina . Kingdom Protista (or Protoctista) is included in the traditional five- or six-kingdom model, where it can be defined as containing all eukaryotes that are not plants, animals, or fungi. Protista
1092-458: The above definitions is the "certain degree" that defines how different organisms need to be members of different phyla. The minimal requirement is that all organisms in a phylum should be clearly more closely related to one another than to any other group. Even this is problematic because the requirement depends on knowledge of organisms' relationships: as more data become available, particularly from molecular studies, we are better able to determine
1131-659: The archaeal-bacterial branch point. However, a close relationship of the Thermotogota to the Aquificota, and the deep branching of the latter group of species, is not supported by phylogenetic studies based upon other gene/protein sequences. and also by conserved signature indels in several highly conserved universal proteins. The Thermotogota have also been scrutinized for their supposedly profuse Lateral gene transfer with Archaeal organisms. However, recent studies based upon more robust methodologies suggest that incidence of LGT between Thermotogota and other groups including Archaea
1170-456: The base. The type species of the genus is T. maritima , first described in 1986. At the time, it was the first species of the phylum to be described. The genus Thermotoga now contains three official species. Recently eight species were transferred out of the genus and most of them ended up within the genus Pseudothermotoga by Bhandari & Gupta 2014. T. subterranea strain SL1 was found in
1209-570: The cells of these species. Recently, some Thermotogota existing at moderate temperatures have also been identified. Although Thermotogota species exhibit Gram-negative staining, they are bounded by a single-unit lipid membrane, hence they are monoderm bacteria. Because of the ability of some Thermotogota species to thrive at high temperatures, they are considered attractive targets for use in industrial processes. The metabolic ability of Thermotogota to utilize different complex-carbohydrates for production of hydrogen gas led to these species being cited as
Thermotogae - Misplaced Pages Continue
1248-507: The first publication of the APG system in 1998, which proposed a classification of angiosperms up to the level of orders , many sources have preferred to treat ranks higher than orders as informal clades. Where formal ranks have been provided, the traditional divisions listed below have been reduced to a very much lower level, e.g. subclasses . Wolf plants Hepatophyta Liver plants Coniferophyta Cone-bearing plant Phylum Microsporidia
1287-411: The next. The Catalogue of Life includes Rhodophyta and Glaucophyta in kingdom Plantae, but other systems consider these phyla part of Protista. In addition, less popular classification schemes unite Ochrophyta and Pseudofungi under one phylum, Gyrista , and all alveolates except ciliates in one phylum Myzozoa , later lowered in rank and included in a paraphyletic phylum Miozoa . Even within
1326-539: The other hand, the highly parasitic phylum Mesozoa was divided into two phyla ( Orthonectida and Rhombozoa ) when it was discovered the Orthonectida are probably deuterostomes and the Rhombozoa protostomes . This changeability of phyla has led some biologists to call for the concept of a phylum to be abandoned in favour of placing taxa in clades without any formal ranking of group size. A definition of
1365-501: The presence of the same CSI within these two unrelated groups of bacteria is not due to lateral gene transfer , rather the CSI likely developed independently in these two groups of thermophiles due to selective pressure . The insert is located on the surface of the protein in the ATPase domain, near the binding site of ADP/ATP. Molecular dynamic stimulations revealed a network of hydrogen bonds formed between water molecules, residues within
1404-482: The relationships among phyla within larger clades like Ecdysozoa and Embryophyta . The term phylum was coined in 1866 by Ernst Haeckel from the Greek phylon ( φῦλον , "race, stock"), related to phyle ( φυλή , "tribe, clan"). Haeckel noted that species constantly evolved into new species that seemed to retain few consistent features among themselves and therefore few features that distinguished them as
1443-475: The relationships between groups. So phyla can be merged or split if it becomes apparent that they are related to one another or not. For example, the bearded worms were described as a new phylum (the Pogonophora) in the middle of the 20th century, but molecular work almost half a century later found them to be a group of annelids , so the phyla were merged (the bearded worms are now an annelid family ). On
1482-474: The term division has been used instead of phylum, although the International Code of Nomenclature for algae, fungi, and plants accepts the terms as equivalent. Depending on definitions, the animal kingdom Animalia contains about 31 phyla, the plant kingdom Plantae contains about 14 phyla, and the fungus kingdom Fungi contains about 8 phyla. Current research in phylogenetics is uncovering
1521-558: Was also supported by seven CSIs. Additionally, some CSIs that provided evidence of LGT among the Thermotogota and other prokaryotic groups were also reported. The newly discovered molecular markers provide novel means for identification and circumscription of species from the phylum in molecular terms and for future revisions to its taxonomy. Additionally, a 51 aa insertion CSI was identified to be specific for all Thermotogales as well as Aquificales , another order comprising hyperthermophilic species. Phylogenetic studies demonstrated that
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