SciencePhysicsChemistry ► Organic Chemistry ► BiologyExtremophiles

X-Philes Master List

Complete List of Extremophilic & Extremotolerant Prokaryotes


This page is under construction.


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).

Taxonomic/Phylogenetic Overview of Extremophilic Genera

Domain: Archaea
Kingdom: Proteoarchaeota
Superphylum: TACK group
Phylum: Thaumarchaeota
Class: Nitrososphaeria (14x; 14-acido)
Order: Nitrosopumilales
Family: Nitrosopumilaceae (10x; 10-acido)
Genus: Candidatus Nitrosoarchaeum (2x; 2-acido)
Genus: Nitrosopumilus (8x; 8-acido)
Order: Nitrososphaerales
Family: Nitrososphaeraceae(4x; 4-acido)
Genus: Candidatus Nitrosocosmicus (1x; 1-acido)
Genus: Candidatus Nitrososphaera (3x; 3-acido)
Class: Incertae sedis
Order: Incertae sedis
Family: Incertae sedis
Genus: Candidatus Nitrosopelagicus (1x; 1-acido)
Class: Incertae sedis
Order: Incertae sedis
Family: Incertae sedis
Genus: Candidatus Nitrosotalea (4x; 4-acido)
Class: Incertae sedis
Order: Incertae sedis
Family: Incertae sedis
Genus: Candidatus Nitrosotenuis (3x; 3-acido;)
Phylum: Crenarchaeota
Class: Thermoprotei
Order: Desulfurococcales
Family: Desulfurococcacae
Genus: Aeropyrum (2x; 2-thermo)
Family: Pyrodictiacae
Genus: Geogemma (1x; 1-thermo)
Genus: Pyrolobus (1x; 1-thermo)
Order: Sulfolobales
Family: Sulfobaceae
Genus: Acidianus (10x; 10-thermoacido)
Genus: Metallosphaera (5x; 5-acido)
Genus: Stygiolobus (1x; 1-thermoacido)
Genus: Sulfolobus (45x; 45-thermo, 13-acido, 13-thermoacido)
Genus: Sulfurisphaera (1x; 1-acido)
Genus: Sulfurococcus (3x; 3-acido)
Class: Incertae sedis
Order: Cenarchaeales
Family: Cenarchaeaceae
Genus: Cenarchaeum (1x; 1-acido)
Kingdom: Archaea Incertae sedis → DPANN group
Superphylum: DPANN group
Phylum: Candidatus Diapherotrites
Class: Diapherotrites Incertae sedis → Iainarchaeum
Order: Diapherotrites Incertae sedis → Iainarchaeum
Family: Diapherotrites Incertae sedis → Iainarchaeum
Genus: Iainarchaeum (1x; 1-acido)
Phylum: Aenigmarchaeota
Class: (unnamed?)
Order: Aenigmarchaeales
Family: (unnamed?)
Genus: Aenigmarchaeum (1x; 1-acido)
Phylum: Nanoarchaeota
Class: (unnamed?)
Order: Nanoarchaeales
Family: Nanoarchaeaceae
Genus: Nanoarchaeum (1x; 1-thermo, 1-acido, 1-thermoacido)
Family: Nanopusillaceae
Genus: Nanobsidianus (1x; 1-thermo, 1-acido, 1-thermoacido)
Genus: Nanopusillus (1x; 1-thermo, 1-acido, 1-thermoacido)
Phylum: Incertae sedis
Class: Incertae sedis
Order: Incertae sedis
Family: Incertae sedis
Genus: Candidatus Mancarchaeum (1x; 1-acido)
Phylum: Candidatus Micrarchaeota
Class: Incertae sedis
Order: Incertae sedis
Family: Incertae sedis
Genus: Candidatus Micrarchaeum (1x; 1-acido)
Phylum: Candidatus Parvarchaeota
Class: Incertae sedis
Order: Incertae sedis
Family: Incertae sedis
Genus: Candidatus Parvarchaeum (2x; 2-acido)
Kingdom: Archaea Incertae sedis → euryarchaeota
Superphylum: Archaea Incertae sedis → euryarchaeota
Phylum: Euryarchaeota
Subphylum: Incertae sedis
Class: Archaeoglobi
Order: Archaeoglobales
Family: Archaeoglobaceae
Genus: Archaeoglobus (5x; 5-thermo)
Subphylum: Stenosarchaea
Class: Stenosarchaea Incertae sedis
Order: Candidatus Nanohaloarchaeota
Family: Nanohaloarchaea
Genus: Haloredivivus (1x; 1-haloacido)
Genus: Nanosalina (1x; 1-thermohaloacido)
Genus: Nanosalinarum (1x; 1-haloacido)
Class: Halobacteria
Order: Halobacteriales
Family: Haloarculaceae
Genus: Haloarcula (7x; 7-halo)
Genus: Halomicrobium (3x; 3-halo)
Genus: Halorhabdus (?-halo)
Genus: Halorientalis (?-halo)
Genus: Halosimplex (?-halo)
Genus: Natronomonas (6x; 6-halo, 1-alkali, 1-haloalkali)
Family: Halobacteriaceae
Genus: Haladaptatus (4x; 4-halo)
Genus: Halalkalicoccus (2x; 2-alkali, 2-halo, 2-haloalkali)
Genus: Halarchaeum (1x; 1-acido, 1-halo, 1-haloacido)
Genus: Haloalcalophilium (1x; 1-alkali, 1-halo, 1-haloalkali)
Genus: Halobacterium (4x; 4-halo, 4-radio)
Genus: Halomarina (3x; 3-halo)
Genus: Halorussus (?-halo)
Genus: Natronoarchaeum (4x; 4-halo)
Genus: Salarchaeum (1x; 1-halo)
Family: Halococceae
Genus: Halococcus
Order: Haloferacales
Family: Haloferacaceae
Genus: Halobellus (9x; 9-halo)
Genus: Haloferax (14x; 14-halo)
Genus: Halopelagius (3x; 3-halo)
Genus: Haloplanus (9x; 9-halo)
Genus: Haloquadratum (1x; 1-halo)
Family: Halorubraceae
Genus: Halobaculum (3x; 3-halo)
Genus: Halogeometricum (1x; 1-halo)
Genus: Halogranum (4x; 4-halo)
Genus: Halolamina (6x; 6-halo)
Genus: Halonotius (4x; 4-halo)
Genus: Halorubrum (37x; 1-alkali, 1-haloalkali, 37-halo)
Order: Natrialbales
Family: Natrialbaceae
Genus: Halobiforma (3x; 3-halo)
Genus: Halopiger (6x; 6-halo)
Genus: Halostagnicola (?x; ?-halo)
Genus: Haloterrigena (?x; ?-halo)
Genus: Halovivax (?x; ?-halo)
Genus: Natrarchaeobaculum (1x, 1-halo)
Genus: Natrialba (7x; 1-thermo, 1-baro, 1-thermobaro, 1-alkali, 1-acido, 1-alkaliacido, 6-halo, 7-radio, 7-hypobaro, 7-cryo, 7-xero, 7-cryohypobaroxero)
Genus: Natrinema (7x; 7-halo)
Genus: Natronobacterium (2x; 2-halo, 1-haloalkali, 1-alkali)
Genus: Natronococcus (4x; 4-halo, 3-haloalkali, 3-alkali)
Genus: Natronolimnohabitans (1x; 1-halo)
Genus: Natronolimnobius (1x; 1-halo)
Genus: Natronorubrum (1x; 1-halo)
Class: Methanomicrobia
Order: Methanomicrobiales
Family: Methanomicrobiaceae
Genus: Methanogenium (?x; ?-thermo)
Order: Methanosarcinales
Family: Methanosarcinaceae
Genus: Methanococcoides (?x; ?-thermo)
Genus: Methanosarcina (?x; ?-thermo)
Subphylum: Incertae sedis
Class: Methanococci
Order: Methacoccales
Family: Methanococcaceae
Genus: Methanocaldococcus (2x; 1-thermo, ?**)
Subphylum: Incertae sedis
Class: Methanopyri
Order: Methanopyrales
Family: Methanopyraceae
Genus: Methanopyrus (1x; 1-thermo)
Subphylum: Incertae sedis
Class: Thermococci
Order: Thermococcales
Family: Thermococcaceae
Genus: Pyrococcus (6x; 6-thermo, 6-radio, 2-baro, 2-radiothermobaro)
Genus: Thermococcus (38x; 38-thermo, 38-radio, 5-baro, 1-acido, 2-alkali)
Subphylum: Incertae sedis
Class: Thermoplasmata
Order: Methanomassiliicoccales
Family: Methanomassiliicoccaceae
Genus: Methanomassiliicoccus (?x; ?-acido)
Order: Thermoplasmatales
Family: Cuniculiplasmaceae
Genus: Cuniculiplasma (1x; 1-acido)
Family: Ferroplasmaceae
Genus: Acidiplasma (2x; 2-acido)
Genus: Ferroplasma (4x; 4-acido)
Family: Picrophilaceae
Genus: Picrophilus (2x; 2-acido)
Family: Thermoplasmataceae
Genus: Thermoplasma (2x; 2-acido)
Family: Incertae sedis
Genus: Thermogymnomonas (?x; 1-acido)

Domain: Bacteria
Kingdom: Fibrobacteres/Chlorobi/Bacteroidetes group
Superphylum: Bacteroides/Chlorobi group
Phylum: Bacteroidetes
Class: Bacteroidia
Order: Bacteroidales
Family: Bacteroidaceae
Genus: Bacteroides (39x; 39-cryo)
Class: Cytophagia
Order: Cytophagales
Family: Cytophagaceae
Genus: Cytophaga (1x; 1-cryo)
Kingdom: Terrabacteria
Phylum: Actinobacteria
Class: Acidimicrobiia
Order: Acidimicrobiales
Family: Acidimicrobiaceae
Genus: Acidiferrimicrobium (1x; 1-acido)
Genus: Acidimicrobium (1x; 1-acido)
Genus: Ferrimicrobium (2x; 2-acido)
Class: Actinomycetia
Order: Micrococcales
Family: Brevibacteriaceae
Genus: Brevibacterium (36x; 36-cryo)
Family: Microbacteriaceae
Genus: Cryobacterium (7x; 7-cryo)
Family: Micrococcaceae
Genus: Arthrobacter (54x; 54-cryo, ?1-hypergeo?)
Class: Rubrobacteria
Order: Rubrobacterales
Family: Rubrobacteraceae
Genus: Rubrobacter (8x; 8-radio)
Phylum: Cyanobacteria/Melainabacteria group
Class: Cyanobacteria
Order: Chroococcidiopsidales
Family: Chroococcidiopsidaceae
Genus: Chroococcidiopsis (?-radiocryo+?)
Phylum: Deinococcota (formerly Deinococcus-Thermus)
Class: Deinococci
Order: Deinococcales
Family: Deinococcaceae
Genus: Deinococcus (85x; 85-cryo, 85-hypobaro, 85-xero, 85-radio, ?85+)
Phylum: Firmicutes
Class: Bacilli
Order: Bacillales
Family: Alicyclobacillaceae
Genus: Alicyclobacillus (1x; 1-thermo, 1-acido, 1-thermoacido, 1-spore)
Family: Bacillaceae
Genus: Bacillus (91x; 91-spore, 6-thermo, 1-acido, ?-thermoacido?)
Genus: Virgibacillus (34x; 34-spore, 9-halo)
Family: Incertae sedis
Genus: Exiguobacterium (?-hypobaro)
Class: Clostridia
Order: Eubacteriales
Family: Clostridiaceae
Genus: Anoxynatronum (1x; 1-alkali)
Genus: Clostridium (155x; 155-spore)
Family: Peptococcaceae
Genus: Desulfotomaculum (31x; 31-spore, 17-thermo, 1-alkali, 3-halo, ?-poly?)
Family: Incertae sedis
Genus: Sulfobacillus (5x; 5-acido, 5-spore)
Kingdom: Bacteria Incertae sedis → acidobacteria/acidobacteriota
Phylum: Acidobacteria/acidobacteriota
Class: Acidobacteriia
Order: Acidobacteriales
Family: Acidobacteriaceae
Genus: Acidobacterium (2x; 2-acido)
Genus: Bryocella (1x; 1-acido)
Genus: Telmatobacter (1x; 1-acido)
Kingdom: Bacteria Incertae sedis → aquificae
Phylum: Aquificae
Class: Aquificidae
Order: Aquificales
Family: Aquifaceae
Genus: Aquifex (2x; 2-thermo)
Genus: Hydrogenobacter (3x; 3-thermo, 2-acido, 2-thermoacido)
Genus: Hydrogenobaculum (1x; 1-thermo, 1-acido, 1-thermoacido)
Kingdom: Bacteria Incertae sedis → desulfobacteriota
Phylum: Desulfobacteriota
Class: Thermodesulfobacteria
Order: Thermodesulfobacteriales
Family: Thermodesulfobacteriaceae
Genus: Geothermobacterium (1x; 1-thermo)
Kingdom: Bacteria Incertae sedis → nirospirae
Phylum: Nitrospirae
Class: Nitrospira
Order: Nitrospirales
Family: Nitrospiraceae
Genus: Leptospirillum (3x; 3-acido)
Kingdom: Bacteria Incertae sedis → proteobacteria
Phylum: Proteobacteria
Class: Acidithiobacilla
Order: Acidithiobacillales
Family: Acidithiobacillaceae
Genus: Acidithiobacillus (7x; 7-acido)
Class: Alphaproteobacteria
Order: Rhodospirallales
Family: Acetobacteraceae
Genus: Acetobacter (29x; 29-acido)
Genus: Acidiphilium (6x; 6-acido)
Genus: Acidocella (3x; 3-acido)
Genus: Acidomonas (1x; 1-acido)
Order: Hyphomonadales
Family: Hyphomonadaceae
Genus: Hyphomonas (11x; 11-cryo)
Class: Betaproteobacteria
Order: Burkholderiales
Family: Alcaligenaceae
Genus: Achromobacter (22x; 22-cryo)
Genus: Alcaligenes (4x; 4-cryo)
Family: Comamonadaceae
Genus: Thiomonas (1x; 1-acido)
Order: Neisseriales
Family: Chromobacteriaceae
Genus: Aquaspirillum (6x; 6-cryo)
Order: Nitrosomonadales
Family: Gallionellaceae
Genus: Gallionella (1x; 1-acido)
Family: Thiobacillaceae
Genus: Thiobacillus (4x; 4-acido)
Class: Gammaproteobacteria
Order: Alteromonadales
Family: Alteromonadaceae
Genus: Alteromonas (29x; 29-cryo)
Family: Colwelliaceae
Genus: Colwellia (23x; 23-cryo, 23-baro, 23-cryobaro)
Family: Shewanellaceae
Genus: Shewanella (8x; 8+-cryo, 7+-baro, 7+-cryobaro)
Order: Chromatiales
Family: Ectothiorhodospiraceae
Genus: Halorhodospira (1x; 1-alkali, 1-halo, 1-haloalkali)
Genus: Thiohalospira (1x; 1-alkali, 1-haloacido, 1-haloalkali)
Order: Pseudomonadales
Family: Moraxellaceae
Genus: Psychrobacter (35x; 35-cryo, 35-radio)
Family: Pseudomonadaceae
Genus: Pseudomonas (5x; 5-cryo)
Clade: Delta/Epsilon subdivisions
Class: Deltaproteobacteria
Order: Desulfobacterales
Family: Desulfobacteraceae
Genus: Desulfobacter (1x; 1-acido)
Genus: Desulfosarcina (1x; 1-acido)
Family: Desulfobulbaceae
Genus: Desulfobulbus (5x; 5-halo)
Order: Desulfovibrionales
Family: Desulfomicrobiaceae
Genus: Desulfomicrobium (2x; 1-thermo, 1-acido+)
Family: Desulfovibrionaceae
Genus: Desulfovibrio (3x; 1-thermo, 1-acido, 1-halo)
Class: Epsilonproteobacteria
Order: Campylobacterales
Family: Helicobacteraceae
Genus: Helicobacter (1x; 1-acido)
Kingdom: Bacteria Incertae sedis → thermotogae
Phylum: Thermotogae
Class: ???
Order: Thermotogales
Family: Thermotogaceae
Genus: Thermotoga (11x; 11-thermo)

Radioresistant Organisms
⚑ = You Are Here.

LUCA: The Last Universal Common Ancestor
The New Spontaneous Generation? "Early-Complexity" Hypotheses for Primordial Life

Journal Links
Nature: International Journal of Science
PMC — PubMed Central
PNAS — Proceedings of the National Academy of Sciences of the United States of America

Catalogue Links
Bone Clones
Skulls Unlimited
The TeacherSource
ThermoFisher Scientific

Magazine Links
National Geographic
Popular Science
Scientific American

Evolution Links
The Phylogeny Explorer Project
Tree of Life Web Project

About GenPan
The Official FAQ

Donate $ to D. J. Scott
Donate an Article
Donate an Image

Social Media Groups