Salmonirosea aquatica gen. nov., sp. nov., a Novel Genus within the Family Spirosomaceae, Was Isolated from Brackish Water in the Republic of Korea

A Gram-stain-negative, obligately aerobic, non-motile, rod-shaped bacterial strain designated SJW1-29(T) was isolated from brackish water samples collected from the Seomjin River, Republic of Korea. The purpose of this study was to characterize strain SJW1-29(T) and determine its taxonomic position as a potential new genus within the family Spirosomaceae. The strain grew within the range of 10-30 degrees C (optimum, 25 degrees C), pH 5.0-10.0 (optimum, 7.0), and 1-4% NaCl (optimum, 3%). Phylogenetic analysis based on the 16S rRNA gene revealed that strain SJW1-29(T) belongs to the family Spirosomaceae and is closely related to Persicitalea jodogahamensis Shu-9-SY12-35C(T) (91.3% similarity), Rhabdobacter roseus R491(T) (90.6%), and Arundinibacter roseus DMA-K-7a(T) (90.0%), while the similarities to strains within the order Cytophagales were lower than 90.0%. The genome is 7.1 Mbp with a G+C content of 50.7 mol%. The use of genome-relatedness indices confirmed that this strain belongs to a new genus. The major polar lipid profile consisted of phosphatidylethanolamine, and MK-7 was the predominant menaquinone. The predominant fatty acids were summed feature 3 (C-16:1 omega 7c and/or C-16:1 omega 6c), iso-C-15:0, iso-C-17:0 3-OH, and C-16:0, representing more than 80% of the total fatty acids. The phenotypic, chemotaxonomic, genetic, and phylogenetic properties suggest that strain SJW1-29(T) represents a novel species within a new genus in the family Spirosomaceae, for which the name Salmonirosea aquatica gen. nov., sp. nov., is proposed. The type strain of Salmonirosea aquatica is SJW1-29(T) (=KCTC 72493(T) = NBRC 114061(T) = FBCC-B16924(T)).