Archaea Master List

Domain Archaea contains the following...

Acidophiles: This group includes organisms capable of thriving in hyperacidic conditions, most of which have an optimal growth pH of 5 or lower (OGpH<5)

Hyperacidotolerant, near-acidophilic neutriphiles: This group includes organisms that have an OGpH slightly above this (e.g., Nanoarchaeum equitans, OGpH=6) but can nonetheless be found flourishing in hyperacidic environments (pH=0.5-1.5).

Domain: Archaea (>485x; >156*, 6**, 1***, 85†, 12††, 1†††, 176‡, 28*†, 1*†‡, 3†‡, 9††‡)

Kingdom: Proteoarchaeota (93x; 60*, 57†, 24*†)

Superphylum: TACK group (93x; 60*, 57†, 24*†)

Phylum: Thaumarchaeota (23x; 23†)

Phylum: Crenarchaeota (70x; 60*, 34†, 24*†)

Kingdom: Archaea Incertae sedis → DPANN group

Superphylum: DPANN group (9x; 3*, 9†, 3*†)

Phylum: Candidatus Diapherotrites (1x; 1†)

Phylum: Aenigmarchaeota (1x; 1†)

Phylum: Nanoarchaeota (3x; 3*, 3†, 3*†)

Phylum: DPANN Incertae sedis → Mancarchaeum (1x; 1†)

Phylum: Candidatus Micrarchaeota (1x; 1†)

Phylum: Candidatus Parvarchaeota (2x; 2†)

Kingdom: Archaea Incertae sedis → euryarchaeota

Superphylum: Archaea Incertae sedis → euryarchaeota

Phylum: Euryarchaeota (>383x; >193*, 6**, 19†, 12††, 176‡, 1***, 1†††, 1*†‡, 3†‡, 9††‡)

“Hypergeophilic genera” and “hypergeotolerant genera” refer here to genera known to include hypergeophilic species and/or species with hypergeotolerances.

Genera containing thermophilic and hyperthermotolerant organisms are marked with an asterisk (*)

Genera containing barophilic and hyperbarotolerant organisms are marked with two asterisks (**)

Genera containing acidophilic and hyperacidotolerant organisms are marked with a dagger (†)

Genera containing alkaliphilic and hyperalkalitolerant organisms are marked with two daggers (††)

Genera containing thermoacidophilic and hyperthermoacidotolerant organisms are marked with an asterisk and a dagger (*†)

Genera containing halophilic and hyperhalotolerant organisms are marked with a double dagger (‡)

Bacteria marked with an asterisk and a degree sign (*°) are endospore-forming polyextremotolerant organisms. Bacterial endospores tend to give the bacteria capable of producing them polyextremotolerance. Endospores are known for being able to survive extremely high doses of radiation, vacuum dessication, extreme heat and cold, lack of nutrients, and in some cases even the passage of hundreds of millions of years (for example, Virgibacillus marismortui (formerly Bacillus marismortui and Bacillus strain 2-9-3) was revived by scientists from 250-million-year-old spores (Vreeland, 2000); for comparison, the first dinosaurs began appearing about 220 MYA — 30 million years later). Although these endospore-forming bacteria can survive a variety of harsh conditions, endospore-formation is not done for reproduction, as with fungal spore formation, but is instead a last-ditch effort to survive conditions the bacterium would not otherwise be able to, which means these critters aren’t true polyextremophiles, because they don’t (necessarily) actually grow better in extreme conditions, and in their endospore form don’t even grow at all.

In addition to other sources cited, much of this information was compiled with the help of NCBI’s Taxonomy Browser.