Arenibacterium halophilum gen. nov., sp. nov., a halotolerant bacterium in the family Rhodobacteraceae isolated from a coastal sand dune

Abstract

A Gram-stain-negative, non-pigmented, non-spore-forming, motile, strictly aerobic bacterial strain, designated CAU 1492T, was isolated from a coastal sand dune and its taxonomic position was examined using a polyphasic approach. Cells of strain CAU 1492T grew optimally at 30 °C, pH 7.0 and in 3 % (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence of CAU 1492T showed that it formed a distinct lineage within the family Rhodobacteraceae as a separate deep branch, with 96.8 % or lower sequence similarity values to representatives of the genera Marivita, Donghicola, Sulfitobacter, Marinovum, Phaeobacter, Primorskyibacter, Roseovarius and Aestuariihabitans. Strain CAU 1492T was closely related to Marivita geojedonensis DPG-138T (96.8 %), Donghicola eburneus SW-277T (96.7 %), Sulfitobacter porphyrae SCM-1T (96.7 %), Marinovum algicola FF3T (96.6 %) and Aestuariihabitans beolgyonensis BB-MW15T (96.4 %) based on 16S rRNA gene sequences. The major cellular fatty acids of strain CAU 1492T were cyclo-C19 : 0 ω8c and summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c). The polar lipid pattern was composed of phosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid and an unidentified aminolipid. The strain contained Q-10 as the sole respiratory quinone. The draft genome of strain CAU 1492T was 4.63 Mb with a DNA G+C content of 63.1 mol%. The genome includes 4292 protein-coding genes and a five rRNA operons. On the basis of the phenotypic, chemotaxonomic and genomic data, strain CAU 1492T represents a novel genus in the family Rhodobacteraceae for which the name Arenibacterium halophilum gen. nov., sp. nov. is proposed. The type strain of Arenibacterium halophilum is CAU 1492T (=KCTC 62998T=NBRC 113696T).