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

Abstract

A novel pale pink-pigmented halophilic archaeon, strain DC30T, was isolated from Aran-Bidgol salt lake, a hypersaline playa in Iran. Cells of strain DC30T were non-motile and pleomorphic, from rods to triangular or disc-shaped. Strain DC30T 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 DC30T 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 DC30T 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 DC30T and other previously described genera of extremely halophilic archaea suggest that strain DC30T 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 DC30T ( = IBRC 10041T = KCTC 4046T).