Haloactinomyces albus gen. nov., sp. nov., isolated from the Dead Sea.

A novel halophilic, filamentous actinomycete strain, designated AFM 10258T, was isolated from a sediment sample collected from the Dead Sea of Israel. The isolate grew with 10-35 % NaCl and did not grow without NaCl. The isolate formed white aerial mycelium and long spore chains, and two spores were separated by sterile mycelium. The spores were non-motile, spherical and rugose-surfaced. The isolate contained meso-diaminopimelic acid as the diagnostic diamino acid and galactose and arabinose as the major whole-cell sugars. The polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and three unknown phospholipids. Major fatty acids were anteiso-C17 : 0, iso-C16 : 0 and iso-C15 : 0. MK-9(H4) was the predominant menaquinone and the DNA G+C content was 62.8 mol%. 16S rRNA gene sequence analysis indicated that strain AFM 10258T shared low sequence similarity with the closely related representatives of the families Pseudonocardiaceae (below 94.47 %) and Actinopolysporaceae (below 93.76 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AFM 10258T formed a robust clade with members of the family Actinopolysporaceae. On the basis of analysis of phenotypic, chemical and molecular characteristics, strain AFM 10258T is considered to represent a novel species of a new genus, for which the name Haloactinomyces albus gen. nov., sp. nov., is proposed. The type strain is AFM 10258T (=DSM 45977T=CGMCC 4.7115T).