Mucilaginibacter celer sp. nov. and Aquirhabdus parva gen. nov., sp. nov., isolated from freshwater

Abstract

Two novel bacteria, designated HYN0043(T) and HYN0046(T), were isolated from a freshwater lake in Korea. 16S rRNA gene sequence phylogeny indicated that strain HYN0043(T) belongs to the genus Mucilaginibacter of the family Sphingobacteriaceae because it showed highest sequence similarity to Mucilaginibacter oryzae (98.2%). The average nucleotide identity between strain HYN0043(T) and M. oryzae was 83.5%, which is clearly below the suggested threshold for species demarcation. Strain HYN0046(T) was found to belong to the family Moraxellaceae and shared highest sequence similarity with Agitococcus lubricus (93.8%). The average amino acid identity values between strain HYN0046(T) and representative type strains of closely related genera (Alkanindiges, Agitococcus and Acinetobacter) were 53.1-60.7 %, implying the novelty of the isolate at the genus level. Phenotypic characteristics (physiological, biochemical and chemotaxonomic) also supported the taxonomic novelty of the two isolates. Thus, we suggest the following names to accommodate strains HYN0043(T) and HYN0046(T): Mucilaginibacter celer sp. nov. (type strain HYN0043(T)=KACC 19184(T)=NBRC 112738(T)) in the family Spingobacteriaceae and phylum Bacteroidetes and Aquirhabdus parva gen. nov., sp. nov. (type strain HYN0046(T)=KACC 19178(T)=NBRC 112739(T)) in the family Moraxellaceae and phylum Proteobacteria.