Gemmobacter aquarius sp. Nov., runella rosea sp. nov. and flavobacterium fluviale sp. nov., isolated from the namhangang river system

Three bacterial strains, namely HYN0069^T, HYN0085^T and HYN0086^T, were isolated from freshwater samples taken from the Namhangan River system in Korea. 16S rRNA gene sequence similarities and phylogenetic tree topologies indicated that the three strains belonged to the genera Gemmobacter, Runella and Flavobacterium by showing the highest sequence similarities with Gemmobacter straminiformis (98.4%), Runella aurantiaca (98.3%) and Flavobacterium chungangense (98.1%). No bacterial species with validly published names showed 98.7% or higher sequence similarity with the novel isolates. The average nucleotide identities between the genome sequences of the three new isolates and the three closest neighbours were 80.2–92.0%, all below the threshold for bacterial species delineation (95–96%). Many biochemical and physiological features also discriminated the isolates from previously known species of the genera Gemmobacter, Runella and Flavobacterium. Based on the phylogenetic and phenotypic data presented in this study, we suggest three novel species with the following names: Gemmobacter aquarius sp. nov. (type strain HYN0069^T=KACC 19488^T=NBRC 113115^T), Runella rosea sp. nov. (type strain HYN0085^T=KACC 19490^T=NBRC 113116^T) and Flavobacterium fluviale sp. nov. (type strain HYN0086^T=KACC 19489^T=NBRC 113117^T).