Natrinema soli sp. nov., a novel halophilic archaeon isolated from a hypersaline wetland.

An extremely halophilic archaeon, designated strain 5-3T, was isolated from a soil sample of Meighan wetland in Iran. Strain 5-3T was strictly aerobic, catalase-positive and oxidase-negative. Cells were Gram-stain-negative, non-motile and ovoid. Colonies of strain 5-3T were cream-coloured. The isolate showed optimum growth at 4.0 M NaCl, 40 °C and pH 7.0. The major polar lipids of the strain were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, two unknown phospholipids and three glycolipids (including one that was chromatographically identical to S2-DGD). The major respiratory quinone was menaquinone MK-8. The G+C content of the genomic DNA was 61.5 mol%. The closest relative was Natrinema salaciae JCM 17869T with 97.3 % similarity in the orthologous 16S rRNA gene sequence. Analysis of 16S rRNA and rpoB' gene sequences indicated that strain 5-3T is a member of the genus Natrinema in the family Natrialbaceae and forms a distinct cluster. On the basis of phylogenetic analysis, and phenotypic and chemotaxonomic characteristics, a novel species of the family Natrialbaceae, Natrinema soli sp. nov., is proposed. The type strain is 5-3T (=IBRC-M 11063T=LMG 29247T).