Halopolyspora alba gen. nov., sp. nov., isolated from sediment

A novel halophilic, filamentous actinomycete, designated strain AFM 10251T, was isolated from a sediment sample collected from the Dead Sea, Israel. The isolate grew with 10–35 % multi-salts, and did not grow without NaCl or MgCl2. The isolate formed a white aerial mycelium, and long chains of arthrospores with more than 10 spores per chain. The spores were spherical or oval with warty surfaces, and sterile mycelium was present between individual spores. The isolate contained meso-diaminopimelic acid and a small proportion of ll-diaminopimelic acid as cell-wall diamino acids, and galactose and arabinose as whole-cell sugars. The major menaquinone was MK-9(H4). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and three unknown phospholipids. Major fatty acids were iso-C16 : 0, iso-C17 : 0, iso-C15 : 0 and anteiso-C17 : 0. The DNA G+C content of strain AFM 10251T was 66.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AFM 10251T and the genus Actinopolyspora formed a distinct lineage. Analysis of the secondary structures of variable areas of the 16S rRNA gene showed that strain AFM 10251T was different from all recognized species of the genus Actinopolyspora and members of the family Pseudonocardiaceae. Analysis of the signature nucleotides of the 16S rRNA gene showed that strain AFM 10251T and Actinopolyspora halophila formed a single group, but with base pair differences at positions 127 : 234 and 183 : 194. On the basis of analysis of chemical and molecular characteristics, strain AFM 10251T is considered to represent a novel species of a new genus in the family Actinopolysporaceae, for which the name Halopolyspora alba gen. nov., sp. nov. is proposed. The type strain of Halopolyspora alba is AFM 10251T ( = DSM 45976T = CGMCC 4.7114T).