Halopenitus persicus gen. nov., sp. nov., an archaeon from an inland salt lake

A novel pale pink-pigmented halophilic archaeon, strain DC30^T, was isolated from Aran-Bidgol salt lake, a hypersaline playa in Iran. Cells of strain DC30^T were non-motile and pleomorphic, from rods to triangular or disc-shaped. Strain DC30^T required at least 1.7 M NaCl and 0.05 M MgCl₂ for growth (optimum, 3 M NaCl and 0.1 M MgCl₂). The optimum pH and temperature for growth of strain DC30^T were pH 7.5 and 40 °C, respectively, although it was capable of growth over pH and temperature ranges of 6.5–8.5 and 25–50 °C, respectively. Analysis of the 16S rRNA gene sequence showed that strain DC30^T was a member of the family Halobacteriaceae. However, it had low 16S rRNA gene sequence similarities of 92.4 %, 89.4 % and 89.1 % to the most closely related haloarchaeal taxa, the type species of the genera Halorubrum, Halogranum and Haloplanus, respectively. The DNA G+C content was 66.0 mol%. Phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester, common phospholipids found in haloarchaea, were present. Three minor phospholipids and one unidentified glycolipid were also observed. The only quinone present was MK-8(II-H₂). The physiological, biochemical and phylogenetic differences between strain DC30^T and other previously described genera of extremely halophilic archaea suggest that strain DC30^T represents a novel species in a new genus within the family Halobacteriaceae, for which the name Halopenitus persicus gen. nov., sp. nov. is proposed. The type strain of Halopenitus persicus is DC30^T ( = IBRC 10041^T = KCTC 4046^T).