Nocardioides ochotonae sp. nov., Nocardioides campestrisoli sp. nov. and Nocardioides pantholopis sp. nov., isolated from the Qinghai–Tibet Plateau

Abstract

Six Gram-stain-positive, aerobic and irregular-rod-shaped actinobacteria (ZJ1313T, ZJ1307, MC1495T, Y192, 603T and X2025) were isolated from the Qinghai–Tibet Plateau of China and were characterized using a polyphasic taxonomic method. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the six new strains formed three distinct clusters within the genus Nocardioides , and strains ZJ1313T and ZJ1307 were most closely related to N. solisilvae JCM 31492T (16S rRNA gene sequence similarity, 98.0 %), MC1495T and Y192 to N. houyundeii 78T (98.5 %), and 603T and X2025 to N. dokdonensis JCM 14815T (97.6 %). The digital DNA–DNA hybridization values of strains ZJ1313T, MC1495T and 603T among each other and with type strains of their closest relatives were all below the 70 % cut-off point, but values within each pair of new strains were all higher than the threshold. The major fatty acids of these strains were iso-C16 : 0, C17 : 1 ω8c or C18 : 1 ω9c. MK-8(H4) was the predominant respiratory menaquinone and ʟʟ−2,6-diaminopimelic acid was the diagnostic diamino acid. All the strains shared diphosphatidylglycerol (predominant), phosphatidylglycerol, phosphatidylcholine and phosphatidylinositol as the common polar lipids, with minor difference in the types of unidentified phospholipids, glycolipids and lipids. The G+C contents based on genomic DNA of strains ZJ1313T, MC1495T and 603T were 72.5, 72.1 and 73.2 mol%, respectively. The above results suggested that strain pairs ZJ1313T/ZJ1307, MC1495T/Y192 and 603T/X2025 represent three new species of genus Nocardioides , for which the names Nocardioides ochotonae sp. nov. (ZJ1313T=GDMCC 4.177T=KCTC 49537T=JCM 34185T), Nocardioides campestrisoli sp. nov. (MC1495T=GDMCC 4.176T=KCTC 49536T=JCM 34307T) and Nocardioides pantholopis sp. nov. (603T=CGMCC 4.7510T=DSM 106494T) are proposed accordingly.

Identification of Nocardioides marmotae sp. nov. and Nocardioides faecalis sp. nov., two new members of the genus Nocardioides

“…MK-8(H 4 ) was the major respiratory quinone detected in strains zg-579 T and zg-536 T , with contents of 68.1 and 88.5 %, respectively. In addition, the two new type strains contained ll -diaminopimelic acid as the diagnostic diamino acid, which was in line with other known species within the genus Nocardioides [20, 27, 28, 50–54]. Strains zg-579 T and zg-536 T shared galactose and ribose in their cell wall, whereas glucose was also found in zg-579 T ; however, data about the cell-wall sugar components of their respective neighbours were not available.…”

“…Generally, the chemotaxonomic features of the two novel species were consistent with those shared by members of the genus Nocardioides [28]. As detailed in Table 2, the major CFAs in zg-579 T /zg-578 differed considerably from their closely related species (N. lianchengensis CGMCC 4.6858 T , N. deserti SC8A-24 T , N. dokdonensis FR1436 T ): C 17 : 1 ω8c (>35 %) was the dominant CFA in zg-579 T /zg-578.…”

“…Generally, the chemotaxonomic features of the two novel species were consistent with those shared by members of the genus Nocardioides [28]. As detailed in , the major CFAs in zg-579 T /zg-578 differed considerably from their closely related species ( N.…”

“…), plants ( Lamiophlomis rotate , Taraxacum officinale , etc. ), and soil, nine novel species within this genus had been identified [11–13, 25, 27, 28]. In this study, a polyphasic taxonomic characterization of another two novel species within this genus was conducted, which were collected from the faeces of Marmota himalayana .…”