gen. nov. sp. nov., a novel member of the family , isolated from the West Pacific Ocean.

Two strains (GL-11-2 and ZH2-Y79) were isolated from the seawater collected from the West Pacific Ocean and the East China Sea, respectively. Cells were Gram-stain-negative, strictly aerobic, non-motile and rod-shaped. Cells grew in the medium containing 0.5-7.5 % NaCl (w/v, optimum, 1.0-3.0 %), at pH 6.0-8.0 (optimum, pH 6.5-7.0) and at 4-40 °C (optimum, 30 °C). HS production occurred in marine broth supplemented with sodium thiosulphate. The almost-complete 16S rRNA gene sequences of the two isolates were identical, and exhibited the highest similarity to JCM 13603 (97.5 %), followed by TW15 (97.2%), DSM 15283 (97.1 %) and ITI-1157 (97.0 %). Phylogenetic analysis revealed that the isolates were affiliated with the family and represented an independent lineage. The sole isoprenoid quinone was ubiquinone 10. The principal fatty acids were summed feature 8 (C 7 and/or C 6) and cyclo-C 8. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and diphosphatidylglycerol. The DNA G+C content was 62.3 mol%. The orthologous average nucleotide identity, DNA-DNA hybridization and average amino acid identity values among the genomes of strain GL-11-2 and the reference strains were 73.2-79.0, 20.3-22.5 and 66.0-80.8 %, respectively. Strains GL-11-2ᵀ and ZH2-Y79 possessed complete metabolic pathways for thiosulphate oxidation, dissimilatory nitrate reduction and denitrification. Phylogenetic distinctiveness, chemotaxonomic differences and phenotypic properties revealed that the isolates represent a novel genus and species of the family , belonging to the class , for which the name gen. nov., sp. nov. (type strain, GL-11-2=KCTC 82723=MCCC M20691) is proposed.