Streptomyces huasconensis sp. nov., an haloalkalitolerant actinobacterium isolated from a high altitude saline wetland at the Chilean Altiplano

Streptomyces strain HST28 T isolated from the Salar de Huasco, an athalassohaline and poly-extreme high altitude saline wetland located in northern Chile, was the subject of a polyphasic taxonomic study. Strain HST28 T showed morphological and chemotaxonomic features in line with its classification in the genus Streptomyces. Optimal growth of strain HST28 T was obtained at 28 °C, pH 8-9 and up to 10 % (w/v) NaCl. Single (16S rRNA) and multi-locus gene sequence analyses showed that strain HST28 T had a distinct phylogenetic position from its closest relatives, the type strains of Steptomyces aureus and Streptomyces kanamyceticus. Digital DNA-DNA hybridization (23.3 and 31.0 %) and average nucleotide identity (79.3 and 85.6 %) values between strain HST28 T and its corresponding relatives mentioned above were below the threshold of 70 and 96 %, respectively, defined for assigning a prokaryotic strains to the same species. Strain HST28 T was characterised by the presence of ll-diaminopimelic acid in its peptidoglycan layer; galactose, glucose, ribose and traces of arabinose and mannose as whole-cell sugars; phosphatidylmethylethanolamine, phosphatidylinositol, aminolipid, glycophospholipid and an unidentified lipid as polar lipids; and the predominating menaquinones MK-9(H6), MK-9(H8) and MK-9(H4) (>20 %) as well as anteiso-C15 : 0 and anteiso-C17 : 0 as major fatty acids (>15 %). Based on the phenotypic and genetic results, strain HST28 T (DSM 107268 T =CECT 9648 T ) merits recognition as a new species named Streptomyces huasconensis sp. nov.