Nocardioides intraradicalis sp. nov., isolated from the roots of Psammosilene tunicoides W. C. Wu et C. Y. Wu.

ABSTRACT

A Gram-stain-positive, non-spore-forming and non-motile strain, designated YIM DR1091T, was isolated from the roots of Psammosilene tunicoides W. C. Wu et C. Y. Wu collected from Gejiu, Yunnan, China. The taxonomic position of strain YIM DR1091T was investigated by a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YIM DR1091T is a member of the genus Nocardioides. Strain YIM DR1091T was closely related to Nocardioides pyridinolyticus OS4T, Nocardioides caricicola YC6903T, Nocardioides hankookensis DS-30T and Nocardioides aquiterrae GW-9T, with which it shared pairwise 16S rRNA gene sequence similarities of 97.6, 97.5, 97.2 and 97.2 %, respectively. Mean DNA-DNA relatedness values between strain YIM DR1091T and related type strains N. pyridinolyticus JCM 10369T, N. caricicola JCM 17686T, N. hankookensis JCM 15302T and N. aquiterrae JCM 11813T were 44.9±1.7, 50.2±1.3, 46.8±0.9 and 43.0±0.2 %, respectively. The respiratory menaquinone for strain YIM DR1091T was MK-8(H4) while the major fatty acids (>5 %) were iso-C16 0, C17 1ω8c, C17 0, iso-C15 0 and iso-C14 0. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol and three unidentified phospholipids. Whole-cell hydrolysates contained mannose, ribose, glucose and galactose, along with ll-diaminopimelic acid as the diagnostic diamino acid in the peptidoglycan. The DNA G+C content was 74.6 mol%. Phenotypic, phylogenetic and chemotaxonomic data indicated that strain YIM DR1091T represents a novel species of the genus Nocardioides, for which the name Nocardioides intraradicalis sp. nov. is proposed. The type strain is YIM DR1091T (=JCM 30632T=CGMCC4.7251T).