Halorussus litoreus sp. nov., isolated from the salted brown alga Laminaria.

A halophilic archaeal strain, designated HD8-51, was isolated from the salted brown alga Laminaria. Cells of strain HD8-51 were motile, pleomorphic coccoid or ovoid, and formed red-pigmented colonies on agar plates. Strain HD8-51 grew optimally at 3.1 M NaCl, 0.03 M MgCl2, 30 °C and pH 7.0. Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 0.85 M. Based on phylogenetic analyses of the 16S rRNA and rpoB' genes, strain HD8-51 was most closely related to members of the genus Halorussus (92.3-95.6 % and 89.2-91.7% similarities, respectively). The average nucleotide identity values and in silico DNA-DNA hybridization values between strain HD8-51 and Halorussus rarus TBN4 were 81.69 and 24.5 %, respectively. The major polar lipids of strain HD8-51 were phosphatidic acid (PA), phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulfate (PGS) and five glycolipids, sulfated galactosyl mannosyl glucosyl diether (S-TGD-1), galactosyl mannosyl glucosyl diether (TGD-1), sulfated mannosyl glucosyl diether (S-DGD-1), mannosyl glucosyl diether (DGD-1) and diglycosyl diether (DGD-2). The DNA G+C content was 65.9 mol%. Based on phenotypic, chemotaxonomic and phylogenetic properties, strain HD8-51 represents a novel species of the genus Halorussus, for which the name Halorussus litoreus sp. nov. is proposed. The type strain is HD8-51 (=CGMCC 1.15333=JCM 31109).