A Gram-stain-negative, non-motile, pleomorphic rod-shaped, orange–red-pigmented, facultatively aerobic and haloalkaliphilic archaeon, strain MK13-1T, was isolated from commercial rock salt imported from Pakistan. The NaCl, pH and temperature ranges for growth of strain MK13-1T were 3.0–5.2 M NaCl, pH 8.0–11.0 and 15–50 °C, respectively. Optimal growth occurred at 3.2–3.4 M NaCl, pH 9.0–9.5 and 45 °C. Addition of Mg2+ was not required for growth. The major polar lipids of the isolate were C20C20 and C20C25 archaeol derivatives of phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester. Glycolipids were not detected. The DNA G+C content was 64.1 mol%. The 16S rRNA gene sequence of strain MK13-1T was most closely related to those of the species of the genus Halorubrum, Halorubrum luteum CECT 7303T (95.9 % similarity), Halorubrum alkaliphilum JCM 12358T (95.3 %), Halorubrum kocurii JCM 14978T (95.3 %) and Halorubrum lipolyticum JCM 13559T (95.3 %). The rpoB′ gene sequence of strain MK13-1T had < 90 % sequence similarity to those of other members of the genus Halorubrum. Based on the phylogenetic analysis and phenotypic characterization, strain MK13-1T may represent a novel species of the genus Halorubrum, for which the name Halorubrum gandharaense sp. nov. is proposed, with the type strain MK13-1T ( = JCM 17823T = CECT 7963T).
An extremely halophilic archaeon, strain DA50T, was isolated from a brine sample of Urmia lake, a hypersaline environment in north-west Iran. Strain DA50T was orange-pigmented, motile, pleomorphic and required at least 2.5 M NaCl but not MgCl2 for growth. Optimal growth was achieved at 4.0 M NaCl and 0.3 M MgCl2. The optimum pH and temperature for growth were pH 7.0 and 45 °C, while it was able to grow over a pH range of 6.5–8.0 and a temperature range of 25–50 °C. Analysis of 16S rRNA gene sequences revealed that strain DA50T is a member of the family Halobacteriaceae, showing a low level of similarity with other members of this family. Highest similarities, 94.4, 94.0 and 93.9 %, were obtained with the 16S rRNA gene sequences of the type strains of Natrialba aegyptia, Halobiforma lacisalsi and Halovivax asiaticus, respectively. Polar lipid analyses revealed that strain DA50T contains phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester. Four unidentified glycolipids and two minor phospholipids were also observed. The only quinone present was MK-8(II-H2). The G+C content of its DNA was 62.3 mol%. On the basis of the data obtained, the new isolate could not be classified in any recognized genus. Strain DA50T is thus considered to represent a novel species of a new genus within the family Halobacteriaceae, order Halobacteriales, for which the name Halovarius luteus gen. nov., sp. nov. is proposed. The type strain of Halovarius luteus is DA50T ( = IBRC-M 10912T = CECT 8510T).
An extremely halophilic archaeal strain, halo-7T, was isolated from brine sediment of the Gomso solar saltern, Republic of Korea. Cells of strain halo-7T were pleomorphic, stained Gram-negative, lysed in distilled water and formed red-pigmented colonies. Strain halo-7T grew in the range of 25–45 °C (optimum 37–40 °C), pH 6.5–9.5 (optimum pH 7.0–8.0), 15–30 % (w/v) NaCl (optimum, 20–25 %), and 0.05–0.5 M MgCl2 (optimum 0.1–0.3 M). The minimal NaCl concentration to prevent cell lysis of strain halo-7T was 10 % (w/v). The major polar lipids of the isolate were phosphatidylglycerol, phosphatidylglycerolphosphate methyl ester, an unidentified phospholipid, an unidentified lipid, and two unidentified glycolipids. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain halo-7T is closely related to the members of the genus Halolamina, Halolamina salina WSY15-H3T (98.7 % 16S rRNA gene sequence similarity), Halolamina pelagica TBN21T (98.2 %) and Halolamina rubra CBA1107T (97.4 %). The genomic DNA G+C content determined for strain halo-7T (68.0 mol%) was slightly higher than those of H. salina JCM 18549T and H. rubra CBA1107T. DNA–DNA hybridization values between strain halo-7T and reference strains were < 25 %. Based on phenotypic, chemotaxonomic and phylogenetic properties, we describe a novel species of the genus Halolamina, represented by strain halo-7T, for which we propose the name Halolamina sediminis sp. nov. The type strain is halo-7T ( = JCM 30187T = CECT 8739T).
A hyperthermophilic crenarchaeon, designated strain CBA1502T, was isolated from volcanic soil in the Mayon volcano in the Philippines. The 16S rRNA gene sequence of strain CBA1502T was most closely related to that of Thermoproteus uzoniensis DSM 5263T (99.2 % similarity) and Thermoproteus tenax Kra 1T (99.0 %). The organism grew at 75–90 °C and pH 4.0–6.0 and in the presence of 0–0.5 % (w/v) NaCl, with optimal growth at 85 °C and pH 5.0. Strain CBA1502T utilized d-arabinose, beef extract, Casamino acids, formate, fumarate, peptone, pyruvate, trimethylamine and yeast extract as energy substrates, and d-arabinose, formate, pyruvate and yeast extract as carbon sources. Fumarate, sulfate, sulfur and thiosulfate functioned as electron acceptors, but not ferric chloride, nitrate, malate or oxidized glutathione. DNA–DNA hybridization studies showed that there was less than 46.1 % relatedness between strain CBA1502T and other members of the genus Thermoproteus. The DNA G+C content of strain CBA1502T was 62.0 mol%. We conclude that, according to its phylogenetic, phenotypic and genotypic characteristics, strain CBA1502T represents a novel species of the genus Thermoproteus, and propose the name Thermoproteus thermophilus sp. nov., with the type strain CBA1502T ( = ATCC BAA-2416T = JCM 17229T).