Flavobacterium sediminis sp. nov., a starch-degrading bacterium isolated from tidal flat sediment.

A yellow-pigmented bacterium with the ability to degrade starch, designated MEBiC07310, was isolated from tidal flat sediment collected in Taean County, Republic of Korea. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain MEBiC07310 was affiliated with the genus Flavobacterium in the phylum Bacteroidetes and showed that the strain was most closely related to Flavobacterium haoranii LQY-7 (96.8 % similarity), followed by Flavobacterium indicum GPTSA 100-9 (95.2 %) and Flavobacterium urocaniciphilum YIT 12746 (94.6 %). Genome-based analysis of the average nucleotide identity (ANI) and in silico DNA-DNA hybridization (DDH) of strain MEBiC07310 compared with F. haoranii LQY-7 and F. indicum GPTSA 100-9 yielded ANI values of 77.0 and 73.3 % and DDH values of 18.0±2.7 and 16.1±3.6 %, respectively. The DNA G+C content of strain MEBiC07310 was 35.2 mol%. Cells of the strain were aerobic, Gram-stain-negative and rod-shaped, and negative for flexirubin-type pigments. Growth was observed at 17-43 °C (optimum 32 °C), at pH 5.0-8.0 (optimum pH 7.0) and with 0-3 % (w/v) NaCl (optimum 1 %). The major fatty acids (>10 %) of strain MEBiC07310 were iso-C15 : 0, iso-C17 : 0 3-OH, summed feature 1 (iso-C15 : 1 H and/or C13 : 0 3-OH) and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c). The major respiratory quinone was menaquinone MK-6. Based on its phenotypic and genotypic characteristics, strain MEBiC07310 should be classified as representing a novel species of the genus Flavobacterium, for which the name Flavobacterium sediminis sp. nov. is proposed. The type strain is MEBiC07310 (=KCTC 62132=JCM 32291).