A haloalkaliphilic archaeon, strain JX313T, was isolated from a saline–alkaline soil from Daqing, Heilongjiang Province, China. Its morphological, physiological and biochemical features and 16S rRNA gene sequence were determined. Colonies of the strain were orange–red and cells were non-motile cocci and Gram-stain-variable. The strain required at least 1.7 M NaCl for growth, with optimal growth occurring in 2.0–2.5 M NaCl. Growth was observed at 20–50 °C and pH 8.0–10.5, with optimal growth at 35 °C and pH 10.0. The G+C content of its genomic DNA was 59.3 mol%. Phylogenetic analysis of 16S rRNA gene sequences showed that strain JX313T is associated with the genera Haloterrigena and Natrinema and is most closely related to Haloterrigena salina XH-65T (96.2 % sequence similarity) and Haloterrigena hispanica FP1T (96.2 %). DNA–DNA hybridization experiments revealed that the relatedness of strain JX313T to type strains of related species of the genus Haloterrigena or Natrinema was less than 50 %. Furthermore, the cellular polar lipids of strain JX313T, identified as phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and mannose-2,6-disulfate (1→2)-glucose glycerol diether (S2-DGD), were consistent with the polar lipid characteristics of the genus Haloterrigena. Therefore, phylogenetic analysis, phenotypic assessment and chemotaxonomic data showed that JX313T represents a novel species within the genus Haloterrigena, for which the name Haloterrigena daqingensis sp. nov. is proposed. The type strain is JX313T (=CGMCC 1.8909T =NBRC 105739T).
A halophilic archaeon, strain RO1-6T, was isolated from a marine solar saltern in eastern China. Cells of strain RO1-6T were pleomorphic and motile and stained Gram-negative. Strain RO1-6T grew well on complex medium and colonies were red-pigmented. It was able to grow at 20–50 °C (optimum 37 °C), in 2.1–5.1 M NaCl (optimum 3.9 M NaCl), in 0.05–0.70 M MgCl2 (optimum 0.30 M MgCl2) and at pH 6.5–8.0 (optimum pH 7.0). Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 12 % (w/v). The major polar lipids of strain RO1-6T were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and two glycolipids that were chromatographically identical to S-DGD-1 and S2-DGD. The 16S rRNA gene sequence of strain RO1-6T showed similarities of 96.9 and 96.4 % to those of the type strains of Halosarcina pallida and Halogeometricum borinquense, respectively, members of the most closely related recognized genera within the family Halobacteriaceae. The DNA G+C content of strain RO1-6T was 61.2 mol%. Phenotypic characterization and phylogenetic analysis revealed that strain RO1-6T is related to Halosarcina pallida and represents a novel species of the genus Halosarcina, for which the name Halosarcina limi sp. nov. is proposed; the type strain is RO1-6T (=CGMCC 1.8711T =JCM 16054T).