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

ABSTRACT

A novel endophytic actinobacterium, designated strain YIM 67072(T), was isolated from healthy roots of Dysophylla stellata (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) NaCl. 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 A3α. The polar lipid profile consisted predominantly of diphosphatidylglycerol and glycolipids. The major fatty acids were anteiso-C15  0, iso-C15  0, anteiso-C17  0 and iso-C16  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 11375(T) (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)).