Kibdelosporangium metalli sp. nov., isolated from a rare earth mine

A Gram-stain-positive, oxidase-negative, catalase-positive isolate forming sporangium-like globular bodies, isolated from the rare earth mine of Bayan Obo in China and designated strain KC 266T, was subjected to a comprehensive taxonomic study. Comparative 16S rRNA gene sequence analysis revealed that strain KC 266T represented a novel lineage within the genus Kibdelosporangium and showed highest 16S rRNA gene similarities to Kibdelosporangiumphilippinense (98.5 %), Kibdelosporangiumaridum subsp. largum (98.2 %), Kibdelosporangiumaridum subsp. aridum (98.2 %) and Kibdelosporangiumphytohabitans (98.0 %). The DNA-DNA relatedness between strain KC 266T and the four species of the genus Kibdelosporangium was less than 60 %. The DNA G+C content of strain KC 266T was 67.9 mol%. The quinone system consisted of major amounts of MK-9(H4) and MK-9(H2), minor amounts of MK-8(H2) and traces of MK-10(H4). The diamino acid of the peptidoglycan was meso-diaminopimelic acid. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylinositol, two unknown phospholipids and one unidentified aminophospholipid. The major cellular fatty acids were iso-C16 : 0, C17 : 1 ω6c, iso-C15 : 0 and iso-C14 : 0. Physiological traits as well as unique traits of the polar lipid profile and the fatty acid pattern distinguished strain KC 266T from the most closely related species. All these results indicate that strain KC 266T represents a novel species of the genus Kibdelosporangium, for which the name Kibdelosporangium metalli sp. nov. is proposed. The type strain is KC 266T (=KCTC 39719T=CCTCC AA 2016002T).