Halobacillus alkaliphilus sp nov., a halophilic bacterium isolated from a salt lake in Fuente de Piedra, southern Spain

A Gram-positive, spore-forming, halophilic bacterial strain, FP5(T), was isolated from a salt lake in southern Spain and subjected to a polyphasic taxonomic study. Strain FP5(T) was strictly aerobic. Cells were coccoidal, occurring singly or in clusters. The cell-wall pepticloglycan type of strain FP5(T) was A4 beta based on L-Orn-D-Asp. Strain FP5(T) was characterized chemotaxonomically by having MK-7 as the major menaquinone and anteiso-C-15:0, anteiso-C-17:0, iso-C-15:0 and iso-C-16:0 as the main fatty acids. The isolate grew optimally at 37 degrees C and in presence of 10 % NaCl; no growth was observed in the absence of NaCl. The DNA G + C content was 43.5 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain FP5(T) falls within the evolutionary radiation of species of the genus Halobacillus. Levels of 16S rRNA gene sequence similarity between strain FP5(T) and the type strains of nine recognized Halobacillus species were in the range 97.0-99.0%. Levels of DNA-DNA relatedness indicated that strain FP5(T) represents a genomic species that is distinct from recognized Halobacillus species. Strain FP5(T) could be differentiated from recognized Halobacillus species based on several phenotypic characteristics. On the basis of phenotypic, phylogenetic and genomic data, strain FP5(T) is considered to represent a novel species of the genus Halobacillus, for which the name Halobacillus alkaliphilus sp. nov. is proposed. The type strain is FP5(T) (=DSM 18525(T) =ATCC BAA-1361(T)).