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

Abstract

A Gram-positive, aerobic actinobacterium with high chromate [Cr(VI)]-reducing ability, designated strain Q5-1T, 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-C14 : 0, iso-C15 : 0, anteiso-C15 : 0 and iso-C16 : 0, and the predominant menaquinone was MK-8(H4). The genomic DNA G+C content was 71.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Q5-1T was closely related to Intrasporangium calvum DSM 43043T ( = NRRL B-3866T) and Humihabitans oryzae KV-657T ( = NRRL B-24470T) with similarities of 96.6 and 96.4 %, respectively. Comparison of phenotypic, biochemical and chemotaxonomic characters of strain Q5-1T 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 Q5-1T ( = KCTC 19811T = CCTCC AA 2010019T = CGMCC 1.10750T = NRRL B-59521T). An emended description of the genus Intrasporangium is also proposed.