A new phylum of Archaea represented by a nanosized hyperthermophilic symbiont

  title={A new phylum of Archaea represented by a nanosized hyperthermophilic symbiont},
  author={Harald Huber and Michael J. Hohn and Reinhard Rachel and Tanja Fuchs and Verena C. Wimmer and K. O. Stetter},
According to small subunit ribosomal RNA (ss rRNA) sequence comparisons all known Archaea belong to the phyla Crenarchaeota, Euryarchaeota, and—indicated only by environmental DNA sequences—to the ‘Korarchaeota’. Here we report the cultivation of a new nanosized hyperthermophilic archaeon from a submarine hot vent. This archaeon cannot be attached to one of these groups and therefore must represent an unknown phylum which we name ‘Nanoarchaeota’ and species, which we name ‘Nanoarchaeum equitans… 
Nanoarchaea: representatives of a novel archaeal phylum or a fast-evolving euryarchaeal lineage related to Thermococcales?
It is indicated that the placement of N. equitans in archaeal phylogenies on the basis of ribosomal protein concatenation may be strongly biased by the coupled effect of its above-average evolutionary rate and lateral gene transfers.
The genome of Nanoarchaeum equitans: Insights into early archaeal evolution and derived parasitism
The hyperthermophile Nanoarchaeum equitans is an obligate symbiont growing in coculture with the crenarchaeon Ignicoccus, and represents a basal archaeal lineage and has a highly reduced genome.
Insights into archaeal evolution and symbiosis from the genomes of a nanoarchaeon and its inferred crenarchaeal host from Obsidian Pool, Yellowstone National Park
Comparison of the N. equitans and Nst1 genomes suggests that the marine and terrestrial lineages of Nanoarchaeota share a common ancestor that was already a symbiont of another archaeon, enabling further studies of the cellular and molecular mechanisms of these relationships.
The Korarchaeota: Archaeal orphans representing an ancestral lineage of life
The cultivation and initial characterization of the first member of the Korarchaeota is described, highly unusual, ultrathin filamentous cells about 0.16 {micro}m in diameter, which likely diverged near the separation of the two major kingdoms of Archaea.
Nanoarchaeal 16S rRNA gene sequences are widely dispersed in hyperthermophilic and mesophilic halophilic environments
The results suggest that nanoarchaeotes are not strictly hyperthermophilic organisms, are not restricted to hyperthernophilic hosts and may be found in a large range of environmental conditions.
Uncultured Archaea in a hydrothermal microbial assemblage: phylogenetic diversity and characterization of a genome fragment from a euryarchaeote.
This study is the first step in using genomics to reveal the physiology of an as yet uncultured group of archaea from deep-sea hydrothermal vents.
Enigmatic, ultrasmall, uncultivated Archaea
Metagenomics has provided access to genomes of as yet uncultivated microorganisms in natural environments, yet there are gaps in our knowledge—particularly for Archaea—that occur at relatively low
High Archaea diversity in Varvara hot spring, Bulgaria
A culture independent molecular phylogenetic analysis revealed high Archaea diversity in a terrestrial hot spring, village Varvara, Bulgaria and characterized the constructed archaeal libraries by the abundance of novel phylotype sequences and the presence of high proportions of Crenarchaeota phylotypes unrelated to cultivated organisms.


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Phylogenetic analysis of ribosomal RNA sequences obtained from uncultivated organisms of a hot spring in Yellowstone National Park reveals several novel groups of Archaea, many of which diverged from
A psychrophilic crenarchaeon inhabits a marine sponge: Cenarchaeum symbiosum gen. nov., sp. nov.
The discovery and preliminary characterization of a marine archaeon that inhabits the tissues of a temperate water sponge and represents the first described symbiosis involving Crenarchaeota, and a symbiotic archaeon closely related to other nonthermophilic cren archaeotes that inhabit diverse marine and terrestrial environments is presented.
Isolation of a hyperthermophilic archaeum predicted by in situ RNA analysis
A procedure to obtain pure cultures of unknown organisms harbouring specific 16S rRNA sequences identified previously within the environment is described, which validates polymerase chain reaction data on the existence of large archaeal communities.
Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya.
It is proposed that a formal system of organisms be established in which above the level of kingdom there exists a new taxon called a "domain." Life on this planet would be seen as comprising three domains, the Bacteria, the Archaea, and the Eucarya, each containing two or more kingdoms.
Reclassification of the crenarchael orders and families in accordance with 16S rRNA sequence data.
A phylogenetic analysis of all validly published members of the Crenarchaeota, including several new isolates from our laboratory, suggests three orders within this archaeal kingdom. The
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The results suggest that hitherto unknown archaea and bacteria may thrive in highly saline brines of the Red Sea under extreme environmental conditions.
Bacterial phylogeny based on comparative sequence analysis (review)
It is shown that only careful data analysis starting with a proper alignment, followed by the analysis of positional variability, rates and character of change, testing various data selections, applying alternative treeing methods and, finally, performing confidence tests, allows reasonable utilization of the limited phylogenetic information.
Identifying members of the domain Archaea with rRNA-targeted oligonucleotide probes
Two 16S rRNA-targeted oligonucleotide probes were designed for the archaeal kingdoms Euryachaeota and Crenarchaeota to facilitate rapid in situ monitoring of the populations present in hydrothermal systems and support cultivation attempts.
The Minimal Gene Complement of Mycoplasma genitalium
Comparison of the Mycoplasma genitalium genome to that of Haemophilus influenzae suggests that differences in genome content are reflected as profound differences in physiology and metabolic capacity between these two organisms.
Global transposon mutagenesis and a minimal Mycoplasma genome.
Global transposon mutagenesis was used to identify nonessential genes in an effort to learn whether the naturally occurring gene complement is a true minimal genome under laboratory growth conditions, and suggests that 265 to 350 of the 480 protein-coding genes of M. genitalium are essential under laboratory growing conditions.