Yimella radicis sp. nov., an endophytic actinobacterium isolated from the root of Paris polyphylla Smith var. yunnanensis.

ABSTRACT

An endophytic actinobacterial strain, designated py1292T, was isolated from the root of Paris polyphylla Smith var. yunnanensis collected from Yunnan province, China, and subjected to a polyphasic taxonomic characterization. Phylogenetic analysis based on 16S rRNA gene sequences placed the isolate in the family Dermacoccaceae and clustered with Yimella lutea (showing the highest similarity of 99.1 %). DNA-DNA relatedness between strain py1292T and Y. lutea YIM 45900T was 45.6±3.2 % (reciprocal 47.8±3.6 %). The novel isolate was found to be a Gram-staining-positive rod, catalase- and oxidase-positive. It grew at pH 6.0-8.0, with 0-9 % NaCl and at 20-45 ºC, optimally at pH 7.0, with 0-3 % NaCl and at 28 ºC. The predominant menaquinone was MK-8(H4), while the polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, two unknown phospholipids and two unknown polar lipids. The major cellular fatty acids were iso-C15 0, iso-C16 0, iso-C17 0 and anteiso-C17 0. The whole-cell hydrolysates contained mannose, ribose, rhamnose, glucose and galactose. The peptidoglycan contained alanine, glycine, serine, aspartic acid, glutamic acid and lysine. The genomic DNA G+C content was determined to be 65.6 mol%. Phylogenetic, phenotypic and chemotaxonomic data (especially the same peptidoglycan type) showed that strain py1292T should be classified as a representative of a novel species of the genus Yimella, for which the name Yimella radicis sp. nov. is proposed. The type strain is py1292T (=KCTC 39612T=LMG 29070T).