Oceanisphaera pacifica sp. nov., isolated from the intestine of Trichiurus japonicus

Abstract

A Gram-stain-negative, strictly aerobic, non-flagellated, oxidase- and catalase-positive, rod-shaped marine bacterium, designated strain DM8T, was isolated from the intestine of Trichiurus japonicus in Weihai, China. The strain optimally grew at 25-35℃, with 1.0-4.0% (w/v) NaCl and at pH 7.0-8.0. Its colonies were circular, slightly yellow, non-transparent, smooth, and approximately 0.8-1.5 mm in diameter, after being cultured for 48h on marine agar 2216. Based on the result of phylogenetic analysis of 16S rRNA gene sequence, strain DM8T had close relationship with Oceanisphaera profunda SM1222T (96.9%) and the similarity between DM8T and the type strain Oceanisphaera litoralis DSM 15406T was 94.7%. Genome sequencing revealed a genome size of 3,109,059 bp and a G+C content of 46.9 mol%. It had Q-8 as the sole respiratory quinone and possessed C16:0, summed features 3 (C16:1ω7c/C16:1ω6c) and summed features 8 (C18:1ω7c/C18:1ω6c) as major fatty acids. The major polar lipid profile was composed of phosphatidylglycerol and phosphatidylethanolamine. Based on the phenotypic, chemotaxonomic characterisations, phylogenetic properties and genome analysis, strain DM8T should represent a novel species of the genus Oceanisphaera, for which the name Oceanisphaera pacifica sp. nov. is proposed. The type strain is DM8T (=KCTC 82764T =MCCC 1K06133T).