Frigoribacterium endophyticum sp nov., an endophytic actinobacterium isolated from the root of Anabasis elatior (C. A. Mey.) Schischk

A novel endophytic actinobacterium, designated EGI 6500707(T), was isolated from the surface-sterilized root of a halophyte Anabasis elatior (C. A. Mey.) Schischk collected from Urumqi, Xinjiang province, north-west China, and characterized using a polyphasic approach. Cells were Gram-stain-positive, non-motile, short rods and produced white colonies. Growth occurred at 10-45 degrees C (optimum 25-30 degrees C), at pH 5-10 (optimum pH 8) and in presence of 0-4% (w/v) NaCL (optimum 0-3%). The predominant menaquinone was MK-9. The diagnostic phospholipids were diphosphatidylglycerol and phosphatidylglycerol. The major fatty acids were anteiso-C-15:0, anteiso-C-17:0 and iso-C-16:0. The DNA G+C content of strain EGI 6500707(T) was 69.1 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain EGI 6500707(T) should be placed in the genus Frigoribacterium (family Microbacteriaceae, phylum Actinobacteria), and that the novel strain exhibited the highest 16S rRNA gene sequence similarity to Frigoribacterium faeni JCM 11265(T) (99.1 %) and Frigoribacterium mesophilum MSL-08(T) (96.5 %). DNA-DNA relatedness between strain EGI 6500707(T) and F. faeni JCM 11265(T) was 47.2%. On the basis of phenotypic and chemotaxonomic characteristics, phylogenetic analysis and DNADNA relatedness data, strain EGI 6500707(T) represents a novel species of the genus Frigoribacterium, for which the name Frigoribacterium endophyticum sp. nov. is proposed. The type strain is EGI 6500707(T) (=JCM 30093(T)=KCTC 294937(T)).