Candidatus Nitrosopumilus

Ni.tro.so.pu'mi.lus. N.L. adj. nitrosus nitrous; L. masc. adj. pumilus dwarf; N.L. masc. n. ca. Nitrosopumilus a dwarf nitrite‐producer. Thaumarchaeota / Nitrososphaeria / Candidatus Nitrosopumilales / Candidatus Nitrosopumilaceae / Candidatus Nitrosopumilus Mesophilic, neutrophilic, autotrophic, and aerobic ammonia‐oxidizing archaea; some species are able to use urea as a source of energy for growth. Slender rods, 0.15–0.27 µm in diameter and 0.49–2.00 µm in length; some species are motile and possess polar to subpolar flagella. Cells are commonly found in marine and brackish environments and have an obligate salt requirement. Cells are sensitive to light. The cell envelope is composed of a monolayer cell membrane, consisting of crenarchaeol as the major glycerol dibiphytanyl glycerol tetraether lipid, and a single S‐layer in a hexagonally ordered pattern as the outermost boundary. Sequence analyses of the 16S rRNA and amoA (encoding the α‐subunit of ammonia monooxygenase) reveal that species of the genus Ca . Nitropumilus comprise a monophyletic group within the family Ca . Nitropumilaceae. The G + C content of the DNA is 33.4–34.2 mol%, which is lower than those of soil and hot spring Thaumarchaeota . DNA G + C content (mol%) : 33.4–34.2. Type species : Candidatus Nitrosopumilus maritimus Könneke, Bernhard, de la Torre, Walker, Waterbury, and Stahl 2005, 545.