Pseudonocardia antimicrobica sp. nov., a novel endophytic actinomycete associated with Artemisia annua L. (sweet wormwood)

Abstract

A Gram-reaction-positive, non-motile, endophytic actinomycete, designated strain YIM 63235 T, was isolated from the surface-sterilized stems of Artemisia annua L., and characterized to determine its taxonomic position. The strain YIM 63235 T formed well-differentiated aerial and substrate mycelia on media tested. The phylogenetic tree based on 16S rRNA gene sequences showed that the new isolate formed a distinct lineage within the genus Pseudonocardia, and the strain YIM 63235 T was closely related to Pseudonocardia parietis 04-St-002 T (99.1%). However, DNA-DNA relatedness demonstrated that strain YIM 63235 T was distinct from the closest phylogenetic neighbor. The chemotaxonomic properties of strain YIM 63235 T were consistent with those of the genus Pseudonocardia: the diagnostic diamino acid of the cell-wall peptidoglycan was meso-diaminopimelic acid and MK-8(H 4) was the predominant menaquinone. The major fatty acids were iso-C 16:0 and iso-C 16:1 H. The DNA GC content of strain YIM 63235 T was 71.0 mol%. On the basis of the phenotypic and phylogenetic distinctiveness, the novel isolate was identified as representing a novel species of the genus Pseudonocardia, for which the name Pseudonocardia antimicrobica sp. nov. (type strain YIM 63235 T CCTCC AA 208080 T DSM 45303 T) is proposed. © 2012 Japan Antibiotics Research Association.