Janthinobacterium aestuarii sp. nov., a novel violacein-producing bacterium isolated from the Tidal Basin in Washington, D.C., USA

Strain TB1-E2-13^T was isolated from water collected from the Tidal Basin in Washington, D.C., USA, due to the bright purple colour of its colonies, and was taxonomically evaluated with a polyphasic approach. Comparison of a partial 16S rRNA gene sequence found that strain TB1-E2-13^T was most similar to species in the <i>Janthinobacterium</i> genus. For more precise taxonomic inference, a phylogenomic analysis was conducted and indicated that strain TB1-E2-13^T was most closely related to <i>Janthinobacterium lividum</i>, '<i>Janthinobacterium kumbetense</i>', <i>Janthinobacterium rivuli</i> and <i>Janthinobacterium violaceinigrum</i>. Analyses of genomic indices found that pairwise comparisons between strain TB1-E2-13^T and other members of the <i>Janthinobacterium</i> genus returned values below the threshold of species novelty. Based on a polyphasic characterization and identifying differences in genomic and taxonomic data, strain TB1-E2-13^T represents a novel species, for which the name <i>Janthinobacterium aestuarii</i> sp. nov. is proposed. The type strain is TB1-E2-13^T (=ATCC TSD-339^T=JCM 36076^T).