Flavobacterium effusum sp. nov., isolated from a freshwater river

A yellowish-orange-coloured bacterial strain, PSI-22^T, was isolated from a freshwater river in Taiwan. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain PSI-22^T belonged to the genus Flavobacterium and showed the highest identity with respect to Flavobacterium dispersum MVW-23^T (98.0 %), Flavobacterium tistrianum GB 56.1^T (97.1 %), Flavobacterium denitrificans ED5^T (97.1 %) and Flavobacterium daemonense THG-DJ7^T (97.0 %) and less than 97 % to other members of the genus. Cells of strain PSI-22^T were Gram-negative, strictly aerobic, motile by gliding and rod-shaped. Optimal growth occurred at 30 °C, pH 6 and in the presence of 0.5 % NaCl. Strain PSI-22^T contained iso-C15 : 0 and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) as the predominant fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, one uncharacterized aminophospholipid, one uncharacterized aminophosphoglycolipid, two uncharacterized aminolipids, one uncharacterized phospholipid and one uncharacterized lipid. The major polyamine was homospermidine. The major isoprenoid quinone was MK-6 and the DNA G+C content of the genomic DNA was 41.4 mol%. The DNA-DNA hybridization value for strain PSI-22^T with F. dispersum BCRC 80978^T, F. tistrianum KCTC 42679^T, F. denitrificans DSM 15936^T and F. daemonense KACC 17651^T was less than 30 %. On the basis of the phylogenetic inference and phenotypic data, strain PSI-22^T should be classified as a novel species, for which the name Flavobacterium effusum sp. nov. is proposed. The type strain is PSI-22^T (=BCRC 80973^T=LMG 29553^T=KCTC 52233^T).