Three novel species of the genus Flavobacterium, Flavobacterium odoriferum sp. nov., Flavobacterium fragile sp. nov. and Flavobacterium luminosum sp. nov., isolated from activated sludge

Three Gram-stain-negative, rod-shaped, non-spore-forming bacteria were isolated from activated sludge samples. The results of phylogenetic analysis based on the 16S rRNA gene sequences indicated that the three strains, designated HXWNR29 T , HXWNR69 T and HXWNR70 T , had the highest sequence similarity to the type strains Flavobacterium cheniae NJ-26 T , Flavobacterium channae KSM-R2A30 T and Flavobacterium amniphilum KYPY10 T with similarities of 97.66 %, 98.66 and 98.14 %, respectively. The draft genomes of these three strains were 2.93 Mbp (HXWNR29 T ), 2.69 Mbp (HXWNR69 T ) and 2.65 Mbp (HXWNR70 T ) long with DNA G+C contents of 31.84 %, 32.83 % and 34.66 %, respectively. These genomes contained many genes responsible for carbohydrate degradation and antibiotic resistance. The major fatty acids (>5 %) included iso-C 15 : 0 , iso-C 15 : 0 3-OH and iso-C 17 : 0 3-OH. The major menaquinone was MK-6 for all the three strains. The average nucleotide identity (ANI; 72.7–88.5 %) and digital DNA–DNA hybridization (dDDH; 19.6–35.3 %) results further indicated that these three strains represented three novel species within the genus Flavobacterium , for which the names Flavobacterium odoriferum sp. nov. (type strain HXWNR29 T = KCTC 92446 T = CGMCC 1.61821 T ), Flavobacterium fragile sp. nov. (type strain HXWNR69 T = KCTC 92468 T = CGMCC 1.61442 T ) and Flavobacterium luminosum sp. nov. (type strain HXWNR70 T = KCTC 92447 T = CGMCC 1.61443 T ) are proposed.