Haloactinospora alba gen. nov., sp. nov., a halophilic filamentous actinomycete of the family Nocardiopsaceae

Abstract

A novel halophilic, filamentous, actinomycete strain, designated YIM 90648(T), was isolated from a salt lake in Xinjiang Province, north-west China, and subjected to a polyphasic taxonomic study. Optimal growth occurred at 37 degrees C, pH 7.0-8.0 and 15% (w/v) NaCl. The aerial mycelium of strain YIM 90648(T) formed long chains of spores at maturity and the spores were cylindrical with smooth surfaces. Spore chains with pseudosporangia at the end were borne on the substrate mycelium and most spores had wrinkled surfaces. Strain YIM 90648(T) contained meso-diaminopimelic acid as the diagnostic diamino acid and galactose and ribose as the major whole-cell components. The phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and phosphatidylinositol mannoside. MK-10(H(8)), MK-11(H(4)), MK-11(H(6)) and MK-11(H(8)) were the predominant menaquinones. The major fatty acids were i-C(16:0) and ai-C(17:0). The DNA G+C content was 68 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YIM 90648(T) formed a distinct lineage within the family Nocardiopsaceae and showed 16S rRNA gene sequence similarity of 93.3-95.0% with members of the family Nocardiopsaceae. On the basis of the polyphasic evidence, a novel genus and species, Haloactinospora alba gen. nov., sp. nov., is proposed to accommodate this isolate. The type strain of Haloactinospora alba is YIM 90648(T) (=DSM 45015(T) =CCTCC AA 206008(T)).