gen. nov. sp. nov., an extremely halophilic archaeon of family isolated from saltpan soil.

A novel archaeal strain designated as SPP-AMP-1 was isolated from saltpan soil, using the serial dilution method on a halophilic archaeal medium supplemented with ampicillin. Cells were both rod-shaped and pleomorphic in nature, non-motile, unable to produce acid from a variety of sugars or grow anaerobically with different substrates (l-arginine) and electron acceptors (DMSO, nitrate). Optimal growth was observed at 42 °C, 3.4-4.2 M NaCl and pH 7.2. Cells did not lyse in distilled water and grew in the absence of Mg ions. Phylogenetic analysis based on the sequences of 16S rRNA gene, amino acid sequence of β'-subunit of RNA polymerase and 400 conserved proteins retrieved from the whole genome assemblies showed that strain SPP-AMP-1 was distantly related to any existing genera within the family . MK-8 was the only quinone detected. Polar lipid analysis showed a unique combination of diethyl derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, glycosyl-mannosyl-glucosyl diether and sulphated glycosyl-mannosyl-glucosyl diether as the major lipids. The G+C content of genomic DNA is 57.7 mol%. The phenotypic, phylogenetic and genomic data supported the concept of the novel genus status of strain SPP-AMP-1 in the family for which the name gen. nov., sp. nov., is proposed; the type strain is SPP-AMP-1 (=JCM 31368=KCTC 4276=MTCC 12579).