Aequorivita iocasae sp. nov., a halophilic bacterium isolated from sediment collected at a cold seep field in the South China Sea

A moderately halophilic bacterium, designated strain KX20305(T), was isolated from sediment collected from a cold seep field in the South China Sea. Cells of strain KX20305(T) were Gram-stain-negative, rod-shaped, non-motile, facultatively anaerobic, oxidase- and catalase-positive, and grew optimally at 25-30 degrees C, pH 6.0-8.0 and with 3-6 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain KX20305(T) grouped with members of the genus Aequorivita , including Aequorivita aquimaris D-24(T) (98.3 % sequence similarity), Aequorivita vladivostokensis KMM 3516(T) (98.1 %) and Aequorivita echinoideorum CC-CZW007(T) (97.5 %). Genome sequencing of strain KX20305(T) revealed a genome size of 3.35 Mb and a DNA G+C content of 38.71 mol%. Genomic average nucleotide identity (orthoANI) values of strain KX20305(T) with A. aquimaris D-24(T), A. vladivostokensis KMM 3516(T) and A. echinoideorum JCM 30378(T) were 83.8, 81.7 and 75.4 %, respectively, while in silico DNA-DNA hybridization (GGDC) values for strain KX20305(T) with these strains were 27.2, 25.0 and 19.6 %, respectively. The major fatty acids of strain KX20305(T) were iso-C-15:0, iso-C-17:0 3-OH and 10-methyl C-16:0/iso-C-17:1 omega 9c. The predominant respiratory quinone was menaquinone-6 (MK-6). The polar lipids mainly comprised phosphatidylethanolamine, two unidentified aminolipids and two unidentified lipids. Based on comparative analysis of phylogenetic, phylogenomic, phenotypic and chemotaxonomic characteristics, strain KX20305(T) represents a novel species of the genus Aequorivita , for which the name Aequorivita iocasae sp. nov. is proposed. The type strain is KX20305(T) (=KCTC 82699(T)=MCCC 1K06238(T)=JCM 34635(T)).