A Gram-negative, pleomorphic, extremely halophilic archaeon, designated strain XH-70T, was isolated from the saline Lake Xilinhot, in Inner Mongolia, China. It formed small (0.9–1.5 mm), red-pigmented, elevated colonies on agar medium. The strain required at least 2.5 M NaCl and 5 mM Mg2+ for growth. The 16S rRNA gene sequence analysis indicated that strain XH-70T belongs to the family Halobacteriaceae, showing 99.5 % similarity to the type strain of Halovivax asiaticus and 94.7 and 94.6 % similarity, respectively, to the type strains of Natronococcus amylolyticus and Natronococcus occultus. Polar lipid analysis supported the placement of strain XH-70T in the genus Halovivax. DNA–DNA hybridization studies (32 % with Halovivax asiaticus CGMCC 1.4248T), as well as biochemical and physiological characterization, allowed strain XH-70T to be differentiated from Halovivax asiaticus. A novel species, Halovivax ruber sp. nov., is therefore proposed to accommodate this strain. The type strain is XH-70T (=CGMCC 1.6204T=DSM 18193T=JCM 13892T).
A Gram-negative, aerobic, neutrophilic and extremely halophilic archaeon (strain AJ201T), isolated from Ayakekum salt lake on the Qinghai–Tibet Plateau, was investigated by a polyphasic approach. The DNA G+C content of strain AJ201T was 65.7 mol%. The major polar lipid profile and phylogenetic analysis based on 16S rRNA gene sequences supported the allocation of the strain to the genus Halorubrum. The results of DNA–DNA hybridizations and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain AJ201T from closely related species. Therefore, strain AJ201T represents a novel species of the genus Halorubrum, for which the name Halorubrum arcis sp. nov. is proposed. The type strain is strain AJ201T (=CGMCC 1.5343T=JCM 13916T).