Haloactinobacterium album gen. nov., sp. nov., a halophilic actinobacterium, and proposal of Ruaniaceae fam. nov.

A Gram-staining-positive, facultatively anaerobic, non-motile and moderately halophilic actinobacterium, designated YIM 93306(T), was isolated from a salt lake in Xinjiang province, north-west China, and subjected to a polyphasic taxonomic study. Strain YIM 93306(T) grew in the presence of 2-16 % (w/v) NaCl and did not grow without NaCl. The peptidoglycan type was A4alpha with an l-Lys-l-Glu interpeptide bridge. The whole-cell sugars were glucosamine, arabinose, mannose and two unknown sugars. The predominant menaquinone was MK-8(H(4)). The major fatty acids were iso-C(15 : 0), anteiso-C(15 : 0) and anteiso-C(17 : 0). The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unknown phosphoglycolipid and one unknown phospholipid. The DNA G+C content was 68.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YIM 93306(T) fell within the radius of the suborder Micrococcineae. Its closest phylogenetic neighbour was the type strain of Ruania albidiflava (AS 4.3142(T); 96.2 % 16S rRNA gene sequence similarity), the sole recognized species of the genus Ruania. Sequence similarities between strain YIM 93306(T) and members of other genera of the suborder Micrococcineae were <95.2 %. On the basis of phylogenetic analysis, phenotypic characteristics and chemotaxonomic differences, a novel genus and species, Haloactinobacterium album gen. nov., sp. nov., is proposed. The type strain of the species is YIM 93306(T) (=DSM 21368(T) =KCTC 19413(T) =CCTCC AB 208069(T)). Based on phylogenetic characteristics and 16S rRNA gene signature nucleotide patterns, the genera Ruania and Haloactinobacterium gen. nov. are proposed to belong to a novel family, Ruaniaceae fam. nov.