Halopiger xanaduensis gen. nov., sp. nov., an extremely halophilic archaeon isolated from saline Lake Shangmatala in Inner Mongolia, China
Strain SH-6T was isolated from the sediment of Lake Shangmatala, a saline lake in Inner Mongolia (China). Cells were pleomorphic. The organism was neutrophilic and required at least 2.5 M (15 %) NaCl, but not MgCl2, for growth; optimal growth occurred at 4.3 M (25 %) NaCl. The G+C content of its DNA was 63.1 mol%. 16S rRNA gene sequence analysis revealed that strain SH-6T is a member of the family Halobacteriaceae, but there was a low level of similarity with other members of this family. Highest sequence similarity (94.6 %) was obtained with the 16S rRNA genes of the type strains of Natronolimnobius innermongolicus and Natronolimnobius baerhuensis. Polar lipid analyses revealed that strain SH-6T contains phosphatidylglycerol and phosphatidylglyceromethylphosphate, derived from both C20C20 and C20C25 glycerol diethers together with the glycolipid S2-DGD-1. On the basis of the data obtained, the new isolate could not be classified in any recognized genus. Strain SH-6T is thus considered to represent a novel species in a new genus within the family Halobacteriaceae, order Halobacteriales, for which the name Halopiger xanaduensis gen. nov., sp. nov. is proposed. The type strain of Halopiger xanaduensis is SH-6T (=CECT 7173T=CGMCC 1.6379T=JCM 14033T).