Actinopolyspora righensis sp. nov., a novel halophilic actinomycete isolated from Saharan soil in Algeria

Abstract

A novel halophilic actinomycete strain, H23(T), was isolated from a Saharan soil sample collected in Djamâa (Oued Righ region), El-Oued province, South Algeria. Strain H23(T) was identified as a member of the genus Actinopolyspora by a polyphasic approach. Phylogenetic analysis showed that strain H23(T) had 16S rRNA gene sequence similarities ranging from 97.8% (Actinopolyspora xinjiangensis TRM 40136(T)) to 94.8% (Actinopolyspora mortivallis DSM 44261(T)). The strain grew optimally at pH 6.0-7.0, 28-32°C and in the presence of 15-25% (w/v) NaCl. The substrate mycelium was well developed and fragmented with age. The aerial mycelium produced long, straight or flexuous spore chains with non-motile, smooth-surfaced and rod-shaped spores. Strain H23(T) had MK-10 (H4) and MK-9 (H4) as the predominant menaquinones. The whole micro-organism hydrolysates mainly consisted of meso-diaminopimelic acid, galactose and arabinose. The diagnostic phospholipid detected was phosphatidylcholine. The major cellular fatty acids were anteiso-C17:0 (37.4%), iso-C17:0 (14.8%), iso-C15:0 (14.2%), and iso-C16:0 (13.9%). The genotypic and phenotypic data show that the strain represents a novel species of the genus Actinopolyspora, for which the name Actinopolyspora righensis sp. nov. is proposed, with the type strain H23(T) (=DSM 45501(T)=CCUG 63368(T)=MTCC 11562(T)).