Microbispora catharanthi sp. nov., a novel endophytic actinomycete isolated from the root of Catharanthus roseus

Abstract

Strain CR1-09^T, an actinomycete isolated from the root of Catharanthus roseus, was taxonomically studied based upon polyphasic approaches. The isolate formed a pair of ovular to circular, smooth-surfaced spores on short sporophores alternately branched from aerial mycelia. It contained meso-diaminopimelic acid in cell wall peptidoglycans. The major menaquinones were MK-9 (H₄) and MK-9 (H₂). The predominant cellular fatty acids were iso-C_{16 : 0} and C_{16 : 0}. The polar lipids profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, hydroxyl phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides, and unidentified ninhydrin positive phosphoglycolipids. Strain CR1-09^T showed the highest 16S rRNA gene sequence similarity with Microbispora tritici DSM 104650^T (99.5 %). Based on the polyphasic approach, DNA-DNA relatedness and average nucleotide identity (ANI), the strain is considered to represent a novel species of the genus Microbispora, for which the name Microbispora catharanthi is proposed. The type strain is strain CR1-09^T (=JCM 30045^T=TISTR 2273^T).

Keywords: 16SrRNA gene; Catharanthus roseus; Microbispora; endophytic actinomycetes; genome; polyphasic taxonomy.