Nocardioides astragali sp. nov., isolated from a nodule of wild Astragalus chrysopterus in northwestern China

A Gram-positive, non-motile, rod-shaped bacterial strain, designated HH06(T), was isolated from a nodule of Astragalus chrysopterus in northwestern China. Phylogenetic analysis of the 16S rRNA gene sequence showed that the strain is closely related to Nocardioides alpinus Cr7-14(T) and Nocardioides furvisabuli DSM 18445(T) with 98.5 and 98.1% similiarity, respectively. Growth was observed at 4–28 °C in R2A medium (optimum at 25 °C), at 10–30 °C in YMA and LB medium (optimum in both at 28 °C) and at pH 5.0–10.0 in R2A medium (optimum at pH 7.0–8.0). The cell wall peptidoglycan was found to contain LL-diaminopimelic acid as the principal diamino acid and MK-8(H4) was identified as the predominant menaquinone. The major polar lipids were identified as phosphatidylinositol, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, two unidentified glycolipids and two unidentified polar lipids. The major fatty acids were identified as iso-C(16:0) (32.8%) and C(18:1) ω9c (15.1%). The DNA G+C content of strain HH06(T) was determined to be 71.4 mol%. Based on phenotypic, chemotaxonomic, phylogenetic properties and DNA–DNA relatedness, it is concluded that strain HH06(T) represents a novel species of the genus Nocardioides, for which the name Nocardioides astragali sp. nov. is proposed. The type strain is HH06(T) (= CGMCC 4.7327(T) = NBRC 112322(T)). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10482-018-1020-1) contains supplementary material, which is available to authorized users.