Ruania rhizosphaerae sp. nov., a novel actinobacterium isolated from rhizosphere of Suaeda aralocaspica

A Gram- stain- positive, non- motile and short rod- shaped actinobacterium, designated strain LNNU 22110T, was isolated from the rhizosphere soil of the halophyte Suaeda aralocaspica (Bunge) Freitag and Schutze, which collected in Xinjiang, north- west China. Growth occurred at 10-45 degrees C, pH 6.0-10.0 and in the presence of 0-11 % NaCl (w/v). Based on the results of 16S rRNA gene sequence phylogenetic analyses, strain LNNU 22110T belonged to the genus Ruania and had 97.5 and 95.5 % sequence similarity to Ruania alba KCTC 19413T and Ruania albidiflava CGMCC 4.3142T, respectively. The digital DNA-DNA hybridization relatedness values between strain LNNU 22110T and R. alba KCTC 19413T and R. albidiflava CGMCC 4.3142T were 23.2 and 19.9 %, respectively. The highest average nucleotide identity value between strain LNNU 22110T and its closest related strain (R. alba KCTC 19413T) was 80.2 %, much lower than the species delineation threshold of 95-96 %. The genome of strain LNNU 22110T was 4.4 Mb, with a genomic DNA G+C content of 68.4 mol%. The diagnostic diamino acids in the peptidoglycan layer of strain LNNU 22110T were lysine, alanine, glycine, glutamic acid and aspartic acid. The predominant menaquinone was MK-8(H4). The major fatty acid (>10 %) was anteiso- C15:0. The polar lipid profile of strain LNNU 22110T included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, diacylated phosphatidyl dimannoside, one unidentified glycolipid and two unidentified phospholipids. According to the phenotypic, phylogenetic and chemotaxonomic results, strain LNNU 22110T is considered to represent a novel species of the genus Ruania, for which the name Ruania rhizosphaerae sp. nov. is proposed. The type strain is LNNU 22110T (=KCTC 39807T=CGMCC 1.17105T).