A bright-red bacterial strain, TAPP3T, was isolated from a freshwater sample taken from the Wanan Creek in Taiwan. Phylogenetic analyses based on 16S rRNA gene sequences revealed that TAPP3T represented a member of the genus Hymenobacter and showed the highest levels of sequence similarity to Hymenobacter ginsengisoli DCY57T (97.0 %) and Hymenobacter marinus KJ035T (96.5 %) and less than 96.2 % with other members of the genus. Cells of TAPP3T were Gram-stain-negative, aerobic, motile by gliding, rods that were surrounded by a thick capsule. Growth occurred at 20-35 °C (optimum, 25-30 °C), at pH 6.5-7.5 (optimum, pH 7) and with 0-1 % NaCl (optimum, 0 %). TAPP3T contained iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 1ω5c as the predominant fatty acids. The major isoprenoid quinone was MK-7. The polar lipid profile consisted of phosphatidylethanolamine, six uncharacterized aminophospholipids and four uncharacterized lipids. The major polyamine was homospermidine. The DNA G+C content of the genomic DNA was 62.8 mol%. The DNA-DNA relatedness of TAPP3T with respect to Hymenobacter ginsengisoli DCY57T was less than 40 %. On the basis of the phylogenetic inference and phenotypic data, TAPP3T should be classified as representing a novel species, for which the name Hymenobacter rivuli sp. nov. is proposed. The type strain is TAPP3T (=BCRC 80979T=LMG 29559T=KCTC 52236T).
Keywords: Bacteroidetes; Cytophagaceae; Cytophagales; Cytophagia; freshwater creek.