Taxonomy and antimicrobial activities of two novel halophilic Saccharomonospora strains isolated in Algerian Sahara soils

Abstract

Two novel halophilic actinomycetes, strains AH35 and AH10, isolated from saline soils obtained from the Algerian Sahara, were subjected to polyphasic taxonomic characterization. The strains showed good growth in medium containing 7, 10 and 15% NaCl with growth at temperatures of 28–42°C. The organism produced light grey-green aerial mycelium with reddish-brown or yellow-brown diffusible pigment. Micromorphology and chemotaxonomic characteristics were consistent with its assignment to the genus Saccharomonospora. Analysis of 16S rDNA gene sequences showed that AH35 and AH10 formed a robust clade with “Actinopolyspora iraqiensis”, Saccharomonospora halophila and Saccharomonospora paurometabolica. However, a number of phenotypic characteristics readily distinguished strains AH35 and AH10 from these three species. The two strains showed antibacterial activity against Gram-negative bacteria such as Klebsiella pneumoniae, Salmonella enterica, Pseudomonas syringae and Agrobacterium tumefaciens.