Intrasporangium chromatireducens sp. nov., a chromate-reducing actinobacterium isolated from manganese mining soil, and emended description of the genus Intrasporangium.

A gram-positive, aerobic actinobacterium with high chromate [Cr(VI)]-reducing ability, designated strain Q5-1(T), was isolated from manganese mining soil in Hunan Province, central-south China. The organism formed branching hyphae and contained ll-diaminopimelic acid in the cell-wall peptidoglycan. The polar lipid profile was characterized by diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified phospholipid. The major fatty acids were iso-C(14 : 0), iso-C(15 : 0), anteiso-C(15 : 0) and iso-C(16 : 0), and the predominant menaquinone was MK-8(H(4)). The genomic DNA G+C content was 71.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Q5-1(T) was closely related to Intrasporangium calvum DSM 43043(T) ( = NRRL B-3866(T)) and Humihabitans oryzae KV-657(T) ( = NRRL B-24470(T)) with similarities of 96.6 and 96.4 %, respectively. Comparison of phenotypic, biochemical and chemotaxonomic characters of strain Q5-1(T) and phylogenetically related strains revealed that the isolate represents a novel species of the genus Intrasporangium, for which the name Intrasporangium chromatireducens sp. nov. is proposed. The type strain is Q5-1(T) ( = KCTC 19811(T) = CCTCC AA 2010019(T) = CGMCC 1.10750(T) = NRRL B-59521(T)). An emended description of the genus Intrasporangium is also proposed.