Micromonospora terminaliae sp. nov., an endophytic actinobacterium isolated from the surface-sterilized stem of the medicinal plant Terminalia mucronata

Abstract

An endophytic actinobacterium, strain TMS7T, was isolated from the stem of a Thai medicinal plant collected from the grounds of the Phujong-Nayoa National park, Ubon Ratchathani province, Thailand. As a result of a polyphasic taxonomy study, this strain was identified as a member of the genus Micromonospora. This strain was a Gram-stain-positive, aerobic actinobacterium with well-developed substrate mycelium with hyphae forming a single microspore was non-motile. Stran TMS7T was identified according to its 16S rRNA gene sequence as a new member of the genus Micromonospora. The closest phylogenetic members sharing a similarity were Micromonospora chersina DSM 44151T at 99.4 % and Micromonospora rosaria DSM 803T, Micromonospora tulbaghiae TVU1T, Micromonospora inositola DSM 43819T and Micromonospora endolithica DSM 44398T all at 99.2 %. Chemotaxonomic data including cell wall components, major menaquinones and major fatty acids confirmed the affiliation of strain TMS7T to the genus Micromonospora. The results of the phylogenetic analysis, addition to physiological and biochemical studies in combination with DNA-DNA hybridization, allowed the genotypic and phenotypic differentiation of strain TMS7T and the most closely related species with validly published names. The name proposed for the novel species is Micromonospora terminaliae sp. nov. The type strain is TMS7T (=DSM 101760T=NRRL B-65345T).