Rothia endophytica sp nov., an actinobacterium isolated from Dysophylla stellata (Lour.) Benth

A novel endophytic actinobacterium, designated strain YIM 67072(T), was isolated from healthy roots of Dysophylla stellate (Lour.) Benth. Cells of this aerobic, cream yellow-coloured strain occurred singly, in pairs or in tetrads, were Gram-stain-positive and ovoid- to spherical-shaped. Strain YIM 67072(T) grew at 4-45 C, pH 5.0-10.0 and in the presence of 0-7% (w/v) NaCI. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 67072(T) belonged to the genus Rothia. The isolate contained MK-7 as the major component of the quinone system. The peptidoglycan type was A3a. The polar lipid profile consisted predominantly of diphosphatidylglycerol and glycolipids. The major fatty acids were anteiso-C-15:0, iso-C-15:0, anteiso-C-17:0 and iso-C-16:0. The DNA G+C content was 53.2 mol%. However, strain YIM 67072(T) differed from its closest relatives Rothia nasimurium CCUG 35957(T) (98.5% 16S rRNA gene sequence similarity), Rothia amarae JCM 11375T (97.6%) and Rothia terrae L-143(T) (97.3%) in many phenotypic characteristics. Moreover, the levels of DNA DNA relatedness between the novel isolate and the three above-mentioned type strains were 28.7 +/- 1.3%, 36.5 +/- 1.2%, 46.8 +/- 1.5 %, respectively. Based on comparative analysis of physiological and chemotaxonomic data, strain YIM 67072(T) represents a novel species of the genus Rothia, for which the name Rothia endophytica sp. nov. is proposed. The type strain is YIM 67072(T) (=DSM 26247(T)=JCM 18541(T)).