Candidatus taxa

largest known bacteria species

Phytoplasmas are obligate intracellular parasites of plant phloem tissue and of the insect vectors that are involved in their plant-to-plant transmission. Phytoplasmas were discovered in 1967 by Japanese scientists who termed them mycoplasma-like organisms. Since their discovery, phytoplasmas have resisted all attempts at in vitro culture in any cell-free medium; routine cultivation in an artificial medium thus remains a major challenge. Phytoplasmas are characterized by the lack of a cell wall, a pleiomorphic or filamentous shape, a diameter normally less than 1 μm, and a very small geno

species of bacterium

disease impacting citrus fruit spread via insects on an international scale

Candidatus Epulopiscium is a genus of Gram-positive bacteria that have a symbiotic relationship with surgeonfish. These bacteria are known for their unusually large size, many ranging from 0.2 - 0.7 mm (200–700 μm) in length. Until the discovery of Thiomargarita namibiensis in 1999, Epulonipiscium species were thought to be the largest bacteria. They are still the largest known heterotrophic bacteria.

thumb|Promethearchaeum syntrophicum cells dividing under SEM (c). [[Cryo-electron tomography image of a single cell (d). White arrows indicate large membrane vesicles. Scale bar = 1 μm (c) and 500 μm (d)]] In prokaryote nomenclature, Candidatus (abbreviated Ca.; Latin for 'candidate of Roman office') is used to name prokaryotic taxa that are well characterized but yet-uncultured. Contemporary sequencing approaches, such as 16S ribosomal RNA sequencing or metagenomics, provide much information about the analyzed organisms and thus allow identification and characterization of individua

candidate species of bacterium

species of bacterium

"Thorarchaeia" is a class within the kingdom Promethearchaeati. The kingdom Promethearchaeati represents the closest prokaryotic relatives of eukaryotes. Since there is such a close relation between the two different domains, it provides further evidence for the two-domain tree of life theory which states that eukaryotes branched from the archaeal domain. Kingdom Promethearchaeati are single cell marine microbes that contain branch-like appendages and have genes that are similar to Eukarya. The kingdom Promethearchaeati is composed of "Thorarchaeia", Promethearchaeia, "Odinarchaeia", and "Heim

The class Zetaproteobacteria is the sixth and most recently described class of the Pseudomonadota. Zetaproteobacteria can also refer to the group of organisms assigned to this class. The Zetaproteobacteria were originally represented by a single described species, Mariprofundus ferrooxydans, which is an iron-oxidizing neutrophilic chemolithoautotroph originally isolated from Kamaʻehuakanaloa Seamount (formerly Loihi) in 1996 (post-eruption). Molecular cloning techniques focusing on the small subunit ribosomal RNA gene have also been used to identify a more diverse majority of the Zetaproteobac

group of archaea found in acid mine drainages around the world

Nanohalarchaeota is a phylum of diminutive archaea with small genomes and limited metabolic capabilities, belonging to kingdom Nanobdellati. They are ubiquitous in hypersaline habitats, which they share with the extremely halophilic haloarchaea.

disease of plants

species of archaeon

Cenarchaeum is a monotypic genus of archaeans in the family Nitrosopumilaceae. The marine archaean Cenarchaeum symbiosum is psychrophilic and is found inhabiting marine sponges. Cenarchaeum symbiosum was initially detected as a major symbiotic microorganism living within (it is an endosymbiont of) the sponge Axinella mexicana. It has been ubiquitously detected in the world oceans at lower abundances, while in some genera of marine sponges it is one of the most abundant microbiome members. Its genome sequence and diversity has been investigated in detail finding unique metabolic products and it

candidate species of bacterium

'"Candidatus Midichloria"' is a candidatus genus of Gram-negative, non-endospore-forming bacteria, with a bacillus shape around 0.45 μm in diameter and 1.2 μm in length. First described in 2004 with the temporary name IricES1, "Candidatus Midichloria" species are symbionts of several species of hard ticks (e.g., Ixodes ricinus and Ixodes uriae of the Ixodidae family). They live in the cells of the ovary of the females of this tick species. These bacteria have been observed in the mitochondria of the host cells, a trait that has never been described in any other symbiont of animals.

group of bacteria

thumb|Like other species of the ant genus Camponotus (carpenter ants), the wood-nesting C. pennsylvanicus (shown here) possesses the obligate bacterial endosymbiont Blochmannia. Blochmannia is a genus of symbiotic bacteria found in carpenter ants (genus Camponotus) and their allies in the tribe Camponotini. As of 2014, Blochmannia has been discovered in the guts of over 60 species across 6 genera within the Camponotini, and is predicted to be pervasive throughout the tribe. Blochmannia was first discovered by zoologist Friedrich Blochmann in 1887, who described "bacteria-like structures" in th

species of bacterium

The '"Candidatus Pelagibacterales"' are an order in the Alphaproteobacteria composed of free-living marine bacteria that make up roughly one in three cells at the ocean's surface. Overall, members of the Pelagibacterales are estimated to make up between a quarter and a half of all prokaryotic cells in the ocean.

The Nitrosopumilales are an order of the Archaea class Nitrososphaeria.

Vampirovibrionophyceae is a class of non-photosynthetic cyanobacteria.

"Omnitrophica" or "Omnitrophota" is a candidate phylum of bacteria with chemolithoautotrophic nutrition. It was previously known as candidate phylum OP3. These bacteria appear to thrive in anoxic environments, such as deep marine sediments, hypersaline environments, freshwater lakes, aquifers, flooded soils, and methanogenic bioreactors. Genomic analyzes have found genes responsible for the construction of magnetosomes, which are also present in other phyla of bacteria. These organelles have magnetic properties, which causes bacteria to orient themselves magnetically in the environment. Omnitr

'"Candidatus Sukunaarchaeum mirabile"' (provisional name) is a species of archaea of which only the DNA is known, but which already presents several particularities: it is a holoparasite of the dinoflagellate Citharistes regius and is the first known parasitic archaean. Its DNA, the smallest known for an archaeon, codes for only proteins necessary for reproduction.

Saccharibacteria, formerly known as TM7, is a major bacterial lineage. It was discovered through 16S rRNA sequencing .

Nitrosopumilus is a genus of archaea. The type species, Nitrosopumilus maritimus, is an extremely common archaeon living in seawater. It is the first member of the Group 1a Nitrososphaerota (formerly Thaumarchaeota) to be isolated in pure culture. Gene sequences suggest that the Group 1a Nitrososphaerota are ubiquitous with the oligotrophic surface ocean and can be found in most non-coastal marine waters around the planet. It is one of the smallest living organisms at 0.2 micrometers in diameter. Cells in the species N. maritimus are shaped like peanuts and can be found both as individuals and