Actinomaduraalgeriensis sp. nov., an actinobacterium isolated from Saharan soil

During the course of a screening programme for new taxa of actinobacteria, a strain designated ACD1T, was isolated from a Saharan soil in the Hoggar region (Algeria). The taxonomic position of this strain was determined using a polyphasic taxonomic approach. The strain was observed to form extensively branched, non-fragmenting substrate mycelium, and aerial mycelium with straight to flexuous, hooked and irregular spirals (1–2 turns) forming short chains of spores. The diamino acid present in the cell wall is meso-diaminopimelic acid. Galactose, glucose, madurose, mannose and ribose occur in whole-cell hydrolysates. The diagnostic phospholipids detected were diphosphatidylglycerol and phosphatidylinositol. The major menaquinones were identified as MK-9 (H4) and MK-9 (H2). The major fatty acids were found to be C16:0, C18:1cis9, iso-C16:0 and 10-methyl C18:0. Phylogenetic analysis based on the 16S rRNA gene showed that the strain belongs to the genus Actinomadura, and is closely related to Actinomadurasediminis DSM 45500T (98.5 % similarity) and Actinomaduracremea subsp. cremea DSM 43676T (98.3 % similarity). However, DNA–DNA hybridization revealed only 48.0 % relatedness with A. sediminis DSM 45500T and 33.2 % relatedness with A. cremea subsp. cremea DSM 43676T. The combined phenotypic and genotypic data showed that the strain represents a novel species of the genus Actinomadura, for which the name Actinomaduraalgeriensis sp. nov. is proposed, with the type strain ACD1T (= DSM 46744T = CECT 8841T).