Flavobacterium ajazii sp. nov., Isolated from Seaweed of Gouqi Island, China

A novel bacterium designated SSM4.2 T was isolated from seaweed of Gouqi Island, which is the center of the Zhoushan fishing ground in the East China Sea. Strain SSM4.2 T was Gram-stain-negative, bright yellow-pigmented, short rod-shaped, non-flagellated, non-spore forming, aerobic and motile by gliding. Growth was observed at 4–37 °C (optimum 25–30 °C), pH 6.0–8.0 (optimum pH 7.0) and 0–2.0% (w/v) NaCl (optimum 0%) concentration. The strain was catalase- and oxidase-positive. Menaquinone-6 (MK-6) was found as the sole respiratory quinone and zeaxanthin as the main carotenoid pigment. The predominant fatty acids (≥ 10%) were iso-C 15:0 , iso-C 15:1 G, iso-C 17:0 3-OH and summed feature 3 (C 16:1 ω 7 c /C 16:1 ω 6 c ). The major polar lipid was phosphatidylethanolamine (PE). The genome size was 5.7 Mbp. The DNA G + C content was 34.1 mol%. 16S rRNA gene sequence revealed that strain SSM4.2 T belongs to the genus Flavobacterium and shares high-sequence similarity with F. limi KACC 18851 T (98.1%), F. hydrophilum KACC 19591 T (97.6%), F. defluvii KCTC 12612 T (97.1%), F. cheongpyeongense KACC 19592 T (97.0%) and F. fluviatile KCTC 52446 T (96.9%). Strain SSM4.2 T had 73.2–84.6% average nucleotide identity and 19.1–29.4% digital DNA-DNA hybridization values with its closest type strains. Based on its phenotypic, chemotaxonomic, phylogenetic and genomic features, strain SSM4.2 T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium ajazii sp. nov. is proposed. The type strain is SSM4.2 T (= KCTC 72807 T = MCCC 1K04370 T ).