Thalassobacillus Cyri Sp Nov., A Moderately Halophilic Gram-Positive Bacterium From A Hypersaline Lake

A Gram-positive, moderately halophilic bacterium, designated strain HS286(T), was isolated from water of the hypersaline Lake Howz-Soltan in Iran. Cells were strictly aerobic, rod-shaped, motile and able to produce ellipsoidal endospores at a central-subterminal position in swollen sporangia. Isolate HS286(T) grew in a complex medium supplemented with 1-15 % (w/v) NaCl, with optimum growth at 8.0% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that strain HS286(T) was closely related to Thalassobacillus devorans G-19.1(T) (99.4% gene sequence similarity). The other closest species were Halobacillus yeomjeoni MSS-402(T) (96.9%) and other species of the genus Halobacillus (with 96.7-93.5% similarity). Strain HS286(T) had cell-wall pepticloglycan based on meso-diaminopimelic acid and MK-7 as the respiratory isoprenoid quinone. The major fatty acids were anteiso-C(15:0) (43.8%), iso-C(16:0) (21.4%), iso-C(14:0) (9.4%), anteiso-C(17:0) (8.7%) and iso-C(15:0) (7.0%) and the polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, two phospholipids and a glycolipid. The DNA G + C content was 43.0 mol%. All of these features confirmed the placement of isolate HS286(T) within the genus Thalassobacillus. However DNA-DNA hybridization between strain HS286(T) and the only recognized species of the genus Thalassobacillus, T devorans G-19.1(T), was 27.3%, showing unequivocally that the novel isolate constituted a new genospecies. Strain HS286(T) could be clearly differentiated from T. devorans and other phylogenetic neighbours on the basis of several phenotypic, genotypic and chemotaxonomic features. Therefore, strain HS286(T) constitutes a novel species, for which the name Thalassobacillus cyri sp. nov. is proposed. The type strain is HS286(T) (=CCM 7597(T)=JCM 15722(T)).