Oceanobacillus halophilus sp. nov., a novel moderately halophilic bacterium from a hypersaline lake.

Abstract

A moderately halophilic bacterium was isolated from a brine sample of a hypersaline lake, Aran-Bidgol, in Iran. The strain, designated J8BT, was Gram-stain-positive, endospore-forming, rod-shaped, strictly aerobic, motile and produced cream colonies. Strain J8BT grew in NaCl at between 3.0-15.0 % (w/v) (optimally at 7.5 % NaCl, w/v), between pH 6.5-9.0 (optimally at pH 8.0) and between 20-45 °C (optimally at 35 °C). Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain J8BT is a member of the genus Oceanobacillus and most closely related to Oceanobacillus profundus CL-MP28T, Oceanobacillus polygoni SA9T and Oceanobacillus oncorhynchi R-2T (96.9 %, 96.3 % and 96.2 % similarities, respectively). The level of DNA-DNA relatedness between the novel isolate and O. profundus IBRC-M 10567T was 10 %. The major cellular fatty acids of the isolate were anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 0. The polar lipid pattern of strain J8BT consisted of phosphatidylglycerol, diphosphatidylglycerol, five phospholipids, two aminolipids and two glycoaminolipids. 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 39.2 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 halophilus sp. nov. is proposed. The type strain is strain J8BT ( = IBRC-M 10444T = DSM 23996T).