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 degrees C, respectively, although it was capable of growth over pH and temperature ranges of 6.5-8.5 and 25-50 degrees 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-H-2). 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)).