Actinopolyspora sabaoui sp. nov., a novel halophilic actinobacterium isolated from Ghardaïa soil, Algeria.

A novel halophilic actinobacterium, designated H202T, was isolated from a Saharan soil in the Ahbès region (Béni-Isguen, Ghardaïa province, South Algeria), and its taxonomic position was determined by a genome-based polyphasic approach. Phylogenetic analysis of the 16S rRNA gene sequence revealed that the strain H202T belonged to the genus Actinopolyspora and showed the highest sequence similarity to Actinopolyspora mzabensis DSM 45460T (99.46%). Comparative genomic analysis based on digital DNA-DNA hybridization (dDDH), average nucleotide identity (ANI) and average amino acid identity (AAI) showed values below the recommended species cut-off thresholds of 70% (dDDH) and 95-96% (ANI and AAI), suggesting that the strain H202T represents a novel species. This strain exhibits the typical characteristics of the genus Actinopolyspora. The cell-wall hydrolysates contained meso-diaminopimelic acid, and the diagnostic whole-cell sugars were arabinose and galactose. Phosphatidylcholine was identified as the diagnostic phospholipid, and the predominant menaquinones were MK-9(H4) and MK-10(H4). The major fatty acids (≥10%) were anteiso-C17:0, iso-C15:0, iso-C16:0 and anteiso-C15:0. The genome size of strain H202T was estimated to be 5.2 Mbp, with a G+C content of 67.5%. Based on these findings, strain H202T is proposed as a representative of a novel species within the genus Actinopolyspora, named Actinopolyspora sabaoui sp. nov. The type strain is H202T (=DSM 46671T=CECT 31287T).