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 degrees 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(H-6), MK-9(H-8) and MK-9(H4) (>20 %) as well as anteiso C-15:0 and anteiso-C-17:0 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.