Halorubrum luteum sp. nov., isolated from Lake Chagannor, Inner Mongolia, China.

A novel halophilic archaeon, strain CGSA15(T), was isolated from water of Lake Chagannor in China. The strain grew optimally at 33-37 degrees C, pH 9.5-10.0 and 4.0-4.3 M NaCl. The major polar lipids were phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester. The genomic DNA G+C content of strain CGSA15(T) was 60.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CGSA15(T) was a member of the genus Halorubrum and was related most closely to Halorubrum alkaliphilum AS 1.3528(T) (96.1 % similarity) and Halorubrum tibetense AS 1.3239(T) (96.9 %). Levels of DNA-DNA relatedness between strain CGSA15(T) and Hrr. alkaliphilum AS 1.3528(T) and Hrr. tibetense AS 1.3239(T) were 36.7 and 28.9 %, respectively. According to the phenotypic and genotypic data presented, strain CGSA15(T) is considered to represent a novel species of the genus Halorubrum, for which the name Halorubrum luteum sp. nov. is proposed. The type strain is CGSA15(T) (=CGMCC 1.6783(T) =CECT 7303(T)).