Oceanobacillus limi sp. nov., a moderately halophilic bacterium from a salt lake

Abstract

A Gram-stain-positive, endospore-forming, rod-shaped, strictly aerobic, moderately halophilic bacterium, designated strain H9B(T), was isolated from a mud sample of the hypersaline lake Aran-Bidgol in Iran. Cells of strain H9B(T) were motile and produced colonies with a yellowish-grey pigment. Growth occurred between 2.5 and 10 % (w/v) NaCl and the isolate grew optimally at 7.5 % (w/v) NaCl. The optimum pH and temperature for growth of the strain were pH 7.0 and 35 °C, respectively, while it was able to grow over pH and temperature ranges of pH 6-10 and 25-45 °C, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain H9B(T) is a member of the genus Oceanobacillus. The closest relative to this strain was Oceanobacillus profundus CL-MP28(T) with 97.1 % 16S rRNA gene sequences similarity. The level of DNA-DNA relatedness between the novel isolate and this phylogenetically related species was 17 %. The major cellular fatty acids of the isolate were anteiso-C15 : 0, anteiso-C17 : 0, iso-C15 : 0 and iso-C16 : 0. The polar lipid pattern of strain H9B(T) consisted of phosphatidylglycerol, diphosphatidylglycerol, four phospholipids and an aminolipid. It contained MK-7 as the predominant menaquinone and meso-diaminopimelic acid in the cell-wall peptidoglycan. The G+C content of the genomic DNA of this strain was 37.1 mol%. Phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data suggest that this strain represents a novel species of the genus Oceanobacillus, for which the name Oceanobacillus limi sp. nov. is proposed. The type strain of Oceanobacillus limi is strain H9B(T) ( = IBRC-M 10780(T) = KCTC 13823(T) = CECT 7997(T)).