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

Abstract

A yellow-pigmented bacterium with the ability to degrade starch, designated MEBiC07310^T, 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^T was affiliated with the genus Flavobacterium in the phylum Bacteroidetes and showed that the strain was most closely related to Flavobacterium haoranii LQY-7^T (96.8 % similarity), followed by Flavobacterium indicum GPTSA 100-9^T (95.2 %) and Flavobacterium urocaniciphilum YIT 12746^T (94.6 %). Genome-based analysis of the average nucleotide identity (ANI) and in silico DNA-DNA hybridization (DDH) of strain MEBiC07310^T compared with F. haoranii LQY-7^T and F. indicum GPTSA 100-9^T 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^T 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^T 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^T 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^T (=KCTC 62132^T=JCM 32291^T).

Keywords: Flavobacterium; starch; tidal flat sediment.