A novel endophytic actinomycete, strain WPS1-2T, isolated from a root of Globba winitii C. H. Wright, was characterized taxonomically by using a polyphasic approach. Strain WPS1-2T exhibited identical characteristics to the members of the genus Micromonospora. Single spores were observed directly on substrate mycelia. The cell-wall peptidoglycan of the strain contained meso-diaminopimelic acid and 3-OH-meso-diaminopimelic acid. Whole-cell hydrolysates contained glucose, ribose, arabinose and xylose. The predominant menaquinones were MK-10(H8) and MK-10(H10). The major cellular fatty acids consisted of iso-C15 : 0, iso-C16 : 0 and anteiso-C15 : 0. According to the 16S rRNA gene sequence of the strain, WPS1-2T showed highest similarity to Micromonospora costi CS1-12T (99.02 %). Phylogenetic analysis of the gyrase subunit B (gyrB) gene indicated that the strain was related to M. costi CS1-12T. The DNA G+C content was 73.7 mol%. The strain could be distinguished from closely related type strains by using a combination of morphological, chemotaxonomic, physiological and biochemical data together with DNA-DNA relatedness values. Based on these observations, strain WPS1-2T is considered to represent a novel species of the genus Micromonospora, for which the name Micromonospora globbae sp. nov. is proposed. The type strain is WPS1-2T (=KCTC 39787T=NBRC 112325T=TISTR 2405T).
Keywords: Globba winitii; Micromonospora globbae; Micromonosporaceae; endophytic actinomycete.