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

A polyphasic taxonomic characterization of two novel strain pairs (designated zg-579 /zg-578 and zg-536 /zg-ZUI104) isolated from the faeces of was conducted based on phylogenetic analysis of the nearly full-length 16S rRNA gene and genome, digital DNA-DNA hybridization, ortho-average nucleotide identity (Ortho-ANI), and phenotypic and chemotaxonomic traits. Comparative analysis of the nearly full-length 16S rRNA gene sequences showed that strain zg-579 was most closely related to FR1436 (97.57 %) and SC8A-24 (97.36 %), whereas strain zg-536 had the highest similarity to MN8 (98.33 %), W2-2-3 (98.26 %) and 2C1-5 (98.19 %). Low levels of DNA-DNA relatedness and Ortho-ANI values (19.8-31.0 %/78.6-88.2 %, zg-579 ; 19.9-31.3 %/78.8-86.2 %, zg-536 ) between the two new type strains and previously known species within the genus support the hypothesis that the four newly characterized strains could be considered to represent two novel species within this genus. The dominant cellular fatty acids found in strain pair zg-536 /zg-ZUI104 were iso-C and C 9 , whereas C 8 was major component in zg-579 /zg-578. Galactose and ribose were the main cell-wall sugars in these two new strain pairs. Diphosphatidylglycerol (DPG), phosphatidylcholine, phosphatidylglycerol (PG) and phosphatidylinositol (PI) were the major polar lipids in zg-579 , whereas DPG, PG and PI predominated in zg-536 . Both strain pairs had MK8(H ) as the major respiratory quinone and ll-diaminopimelic acid as the major cell-wall peptidoglycan. The optimal growth conditions for the two novel strain pairs were 30 °C, pH 7.0 and 0.5 % NaCl (w/v). Based on these polyphasic characterizations, two novel species within the genus are proposed, i.e. sp. nov. and sp. nov., with zg-579 (=CGMCC 4.7663 =JCM 33892 ) and zg-536 (=CGMCC 4.7662 =JCM 33891 ) as the type strains.