Fluviibacter phosphoraccumulans gen. nov., sp. nov., a polyphosphate-accumulating bacterium of Fluviibacteraceae fam. nov., isolated from surface river water

Three aerobic, Gram-stain-negative, non-motile, rod-shaped bacteria, designated as strains SHINM1 T , ICHIJ1 and ICHIAU1, were isolated from surface river water (Saitama Prefecture, Japan). Phylogenetic analyses based on 16S rRNA and 40 marker gene sequences revealed that the strains formed a distinct phylogenetic lineage within the order Rhodocyclales . The three strains shared 100 % 16S rRNA gene similarity. Growth occurred at 15–30 °C and pH 6.0–9.5, but not in the presence of ≥1.0 % (w/v) NaCl. The isolates stained positive for intracellular polyphosphate granules. The major cellular fatty acids were C 16 : 0 , summed feature 2 (C 12 : 1 aldehyde and/or iso-C 16 : 1 I and/or C 14 : 0 3-OH), summed feature 3 (C 16 : 1 ω 7 c and/or C 16 : 1 ω 6 c ) and summed feature 8 (C 18 : 1 ω 7 c and/or C 18 : 1 ω 6 c ). The major polar lipids were phosphatidylethanolamine and an unidentified phospholipid. The predominant quinone system of strain SHINM1 T was ubiquinone-8 and its DNA G+C content was 56.7 mol%. Genome sequencing of the three isolates revealed a genome size of 2.29–2.43 Mbp and average nucleotide identity by orthology values of ≥98.9 %. Based on the results of phenotypic and phylogenetic analyses, strains SHINM1 T , ICHIJ1 and ICHIAU1 represent a novel species of a new genus, for which the name Fluviibacter phosphoraccumulans gen. nov., sp. nov. is proposed, within a new family, Fluviibacteraceae fam. nov. of the order Rhodocyclales . The type strain is SHINM1 T (=JCM 32071 T =NCIMB 15105 T ).