Halobacterium noricense sp nov., an archaeal isolate from a bore core of an alpine Permian salt deposit, classification of Halobacterium sp NRC-1 as a strain of H-salinarum and emended description of H-salinarum

Two rod-shaped haloarchaeal strains, A1 and A2, were isolated from a bore core from a salt mine in Austria. The deposition of the salt is thought to have occurred during the Permian period ( 225 - 280 million years ago). The 16S rDNA sequences of the strains were 97.1% similar to that of the type species of the genus Halobacterium, which was also determined in this work. Polar lipids consisted of C-20 - C-20 derivatives of phosphatidylglycerol, methylated phosphatidylglycerol phosphate, phosphatidylglycerol sulfate, triglycosyl diether and sulfated tetraglycosyl diether. Optimal salinity for growth was 15 - 17.5% NaCl; Mg++ was tolerated up to a concentration of 1 M. The DNA - DNA reassociation value of strain A1(T) was 25% with H. salinarum DSM 3754(T) and 41% with Halobacterium sp. NRC-1, respectively. Based on these results and other properties, e. g. whole cell protein patterns, menaquinone content and restriction patterns of DNA, strains A1 and A2 are members of a single species, for which we propose the name H. noricense. The type strain is A1 ( DSM 15987(T), ATCC BAA-852(T), NCIMB 13967(T)). Since we present evidence that Halobacterium sp. NRC-1 is a member of H. salinarum, an emended description of H. salinarum is provided.