Abstract

A novel bacterial strain, designated ARSA-111T, was isolated from a freshwater reservoir in Cheonan, Korea. Phylogenetic analysis based on 16S rRNA gene sequences suggested that the isolate belonged to the genus Flavobacterium of phylum Bacteroidetes. The 16S rRNA gene sequence of strain ARSA-111T showed a high degree of sequence similarity to those of Flavobacteium cheonanense KACC 14972T (97.3%), F. aquatile JCM 20475T (97.1%), and other type strains of the genus Flavobacterium (＜97.0%). The phylogenetic tree and network analysis (i.e. median-joining) based on 16S rRNA gene sequences showed that strain ARSA-111T is most closely related to F. aquatile JCM 20475T. DNA-DNA hybridization experiment revealed ＜70% of genomic relatedness among strain ARSA-111T, F. aquatile JCM 20475T and F. cheonanense KACC 14972T. The isolate had iso-C15:1, iso-C15:0, and iso-C15:0 3-OH as predominant cellular fatty acids and MK-6 as a predominant menaquinone. The genomic DNA G+C content of the isolate was 35.6 mol%. On the basis of these data, strain ARSA-111T is considered to be a novel species of the genus Flavobacterium, for which the name Flavobacterium aquaticum sp. nov. is proposed. The type strain is strain ARSA-111T (=KACC 14973T =KCTC 23185T = JCM 17070T).

• Keywords: Flavobacterium; Bacteroidetes; median-joining; network