Picrophilus

Picrophilus is a genus of archaeans in the family Picrophilaceae.^[2]

Picrophilus
Scientific classification
Domain:	Archaea
Kingdom:	Methanobacteriati
Phylum:	Thermoplasmatota
Class:	Thermoplasmata
Order:	Thermoplasmatales
Family:	Picrophilaceae
Genus:	Picrophilus Schleper et al. 1996[1]
Type species
Picrophilus oshimae [citation needed] Schleper et al. 1996
Species[1]
Picrophilus oshimae Schleper et al., 1996 Picrophilus torridus Zillig et al., 1996

Schematic map of the pPO1 plasmid from the hyperacidophile Picrophilus oshimae

Picrophilus is an extremely acidophilic genus within Euryarchaeota. These microbes are the most acidophilic organisms currently known,^[3] with the ability to grow at a pH of less than 0.5.^[4] They were first isolated from samples taken from acidic hot springs and dry hot soil in Hokkaido (Japan). They are obligate acidophiles and are unable to maintain their membrane integrity at pH values above 4. While phylogenetically related to other organisms within Thermoplasmata, unlike Thermoplasma and Ferroplasma, Picrophilus contains an S-layer cell wall.