Piscibacillus halophilus sp. nov., a moderately halophilic bacterium from a hypersaline Iranian lake

A Gram-positive, moderately halophilic bacterium, designated strain HS224(T), was isolated from the hypersaline lake Howz-Soltan in Iran. Cells of strain HS224(T) were rod-shaped, motile and produced oval endospores. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain HS224(T) was affiliated to the genus Piscibacillus, exhibiting 98.5 % sequence similarity to the type strain of Piscibacillus salipiscarius. Strain HS224(T) was also related closely to the type strains of Aquisalibacillus elongatus (98.0 % 16S rRNA gene sequence similarity), Filobacillus milosensis (97.9 %) and Tenuibacillus multivorans (97.0 %). Strain HS224(T) was able to grow at NaCl concentrations of 1-20 % (w/v), with optimum growth occurring at 10 % (w/v) NaCl. The optimum temperature and pH for growth were 35 degrees C and pH 7.5. Major polar lipids were phosphatidylglycerol and diphosphatidylglycerol, the isoprenoid quinone was MK-7 and the peptidoglycan type was A1gamma, with meso-diaminopimelic acid as the diagnostic diamino acid; these characteristics were shared with P. salipiscarius. The major cellular fatty acids of strain HS224(T) were anteiso-C(15 : 0), iso-C(15 : 0), anteiso-C(17 : 0) and iso-C(16 : 0). The G+C content of the DNA was 37.5 mol%. The level of DNA-DNA relatedness between strain HS224(T) and P. salipiscarius JCM 13188(T) was 30.8 %. It is evident from the genotypic, chemotaxonomic and phenotypic data presented that strain HS224(T) represents a novel species of the genus Piscibacillus, for which the name Piscibacillus halophilus sp. nov. is proposed. The type strain is HS224(T) (=CCM 7596(T)=DSM 21633(T)=JCM 15721(T)=LMG 24786(T)).