Fluviicoccus keumensis gen. nov., sp. nov., isolated from freshwater

A Gram-stain-negative, non-spore-forming and coccus-shaped bacterial strain, designated 4DR5T, was isolated from freshwater and its taxonomic position was investigated using a polyphasic approach. Growth occurred at 10-40 °C (optimum 30 °C), at pH 6-9 (optimum pH 7) and in the presence of 0-0.4 % (w/v) NaCl (optimum 0 %) on R2A agar. On the basis of 16S rRNA gene sequence similarity, strain 4DR5T was assigned to the family Moraxellaceae of the class Gammaproteobacteria, and its closest related taxa were species of the genera Perlucidibaca (93.67 % sequence similarity), Agitococcus (93.07 %), Paraperlucidibaca (92.31-92.38 %), Alkanindiges (91.79 %) and Acinetobacter (90.24-91.23 %). The predominant isoprenoid quinone detected in strain 4DR5T was Q-10. The major cellular fatty acids were a summed feature consisting of C16 : 1ω7c and/or C16 : 1ω6c, one consisting of C18 : 1ω7c and/or C18 : 1ω6c, and C16 : 0. The major polar lipid was phosphatidylethanolamine. The genomic DNA G+C content of the strain was 61.2 mol%. The phylogenetic, chemotaxonomic and biochemical data not only supported the affiliation of strain 4DR5T to the family Moraxellaceae, but also separated it from other established genera within the family. Therefore, the novel isolate evidently represents a novel species of a new genus of Moraxellaceae, for which the name Fluviicoccus keumensis gen. nov., sp. nov. is proposed. The type strain of Fluviicoccus keumensis is 4DR5T ( = KCTC 32475T = JCM 19370T).