Abstract

A non-motile, yellow-pigmented bacterial strain, designated IMCC34762T, was isolated from a freshwater sample collected from Lake Cheongpyeong in Korea. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain IMCC- 34762T formed a lineage within the genus Flavobacterium and was most closely related to F. pectinovorum DSM 6368T (98.3% sequence similarity), followed by F. piscis CCUG 60099T (98.3%), F. branchiicola 59B-3-09T (98.2%), and F. saccharophilum DSM 1811T (98.2%). The average nucleotide identity and the genome-to-genome distance between strain IMCC34762T and the closely related strains were 61–62% and 26–27%, respectively, indicating that IMCC34762T is a novel species of the genus Flavobacterium. The major fatty acids (> 5%) of strain IMCC34762T were summed feature 3 (C16:1 ω6c and/or C16:1 ω7c, 17.3%), iso-C15:0 (15.0%), iso-C15:0 G (9.0%), C15:0 ω6c (7.4%), iso-C15:0 (7.4%), and iso-C16:0 (5.3%). The major respiratory quinone and polyamine were MK-6 and sym-homospermidine, respectively. The major polar lipids were phosphatidylethanolamine, an unidentified aminophospholipid, and an unidentified lipid. The DNA G+C content of strain IMCC34762T was 34.4 mol%. Based on the taxonomic data presented in this study, strain IMCC34762T represents a novel species within the genus Flavobacterium, for which the name Flavobacterium aquariorum, sp. nov. is proposed. The type strain is IMCC34762T (= KACC 19725T = NBRC 113425T).

• Keywords: Flavobacterium; F. aquariosum; Han River; taxonomy; genome; bacteria