[1] Natronomonas pharaonis is an aerobic, extremely haloalkaliphilic archaeon that grows optimally in 3.5M sodium chloride and at pH 8.5, but is sensitive to high magnesium concentrations.
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN)[2] and National Center for Biotechnology Information (NCBI).
This is considered to be one of the adaptive features of haloarchaea, which are known to apply the salt-in strategy (high internal salt concentrations) in order to survive in their hypersaline environment (Falb et al.).
The archaeon grows under highly alkaline conditions of pH around 11, which causes reduced levels of ammonia in addition to low availability of metal ions.
This is evident from the occurrence of conserved ferredoxin-binding residues within the N. pharaonis NirA protein and ferredoxin dependence of nitrate and nitrite reductases in the halophile Haloferax mediterranei.