Limimonas halophila gen. nov., sp nova, an extremely halophilic bacterium in the family Rhodospirillaceae

A novel, Gram-staining-negative, non-pigmented, rod-shaped, strictly aerobic, extremely halophilic bacterium, designated strain IA16(T), was isolated from the mud of the hypersaline Lake Aran-Bidgol, in Iran. Cells of strain IA16(T) were not motile. Growth occurred with 2.5-5.2 M NaCl (optimum 3.4 M), at pH 6.0-8.0 (optimum pH 7.0) and at 30-50 degrees C (optimum 40 degrees C). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain IA16(T) belonged in the family Rhodospirillaceae and that its closest relatives were Rhodovibrio sodomensis DSM 9895(T) (91.6% sequence similarity), Rhodovibrio salinarum NCIMB 2243(T) (91.2%), Pelagibius litoralis CL-UUO2(T). (88.9 %) and Fodinicurvata sediminis YIM D82(T) (88.7%). The novel strain's major cellular fatty acids were C-19:0 cyclo omega 7c and C-18:0 and its polar lipid profile comprised phosphatidylglycerol, diphosphatidylglycerol, four unidentified phospholipids, three unidentified aminolipids and two other unidentified lipids. The cells of strain IA16(T) contained the ubiquinone Q-10. The G+C content of the novel strain's genomic DNA was 67.0 mol%. The physiological, biochemical and phylogenetic differences between strain IA16(T) and other previously described taxa indicate that the strain represents a novel species in a new genus within the family Rhodospirillaceae, for which the name Limimonas halophila gen. nov., sp. nov. is proposed. The type strain of Limimonas halophila is IA61(T) (=IBRC-M 10018(T) =DSM 25584(T)).