A yellow pigmented, Gram-stain-negative, aerobic bacterium
designated A5.7T was studied to evaluate the taxonomic position
following the modern polyphasic approach. The strain
was isolated from sediments near Zhairuo Island, which is
situated in the East China Sea. Cells were non-spore forming
rods without flagella but showed motility by gliding. Growth
was observed at 15–35°C (optimum 28°C), pH 6.0–9.0 (optimum
pH 6.5) and 0–2% (w/v) NaCl (optimum 0–0.5%) in
LB broth. The major respiratory quinone of A5.7T was menaquinone
6. The major polar lipid of A5.7T was phosphatidylethanolamine
and the predominant fatty acids (> 5%) were
iso-C15:0, iso-C17:0 3-OH, C15:1 ω6c, iso-C15:0 3-OH, iso-C15:1 G,
summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) and summed
feature 9 (iso-C17:1 ω9c and/or C16:0 10-methyl). Phylogenetic
analysis based on 16S rRNA gene sequences showed that the
isolate belongs to the genus Flavobacterium and shares the
highest sequence similarities with Flavobacterium sharifuzzamanii
A7.6T (98.5%), Flavobacterium tistrianum GB 56.1T
(98.3%), Flavobacterium nitrogenifigens NXU-44T (97.8%),
Flavobacterium anhuiense D3T (97.6%), Flavobacterium ginsenosidimutans
THG 01T (97.6%), and Flavobacterium foetidum
CJ42T (97.6%). Digital DNA-DNA hybridization and
average nucleotide identity values between the strain and its
closest phylogenetic neighbors showed the ranges from 19.6
to 34.1% and 73.7 to 87.9%, respectively. Therefore, based
on polyphasic characteristics, strain A5.7T represents a novel
species of the genus Flavobacterium for which the name Flavobacterium
zhairuonensis sp. nov. is proposed. The type
strain is A5.7T (= KCTC 62406T = MCCC 1K03494T).