Genome taxonomy of the genus Thalassotalea and proposal of Thalassotalea hakodatensis sp. nov. isolated from sea cucumber larvae

Abstract

The genus Thalassotalea is ubiquitous in marine environments, and up to 20 species have been described so far. A Gram-staining-negative, aerobic bacterium, designated strain PTE2T was isolated from laboratory-reared larvae of the Japanese sea cucumber Apostichopus japonicus. Phylogenetic analysis based on the 16S rRNA gene nucleotide sequences revealed that PTE2T was closely related to Thalassotalea sediminis N211T (= KCTC 42588T = MCCC 1H00116T) with 97.9% sequence similarity. ANI and in silico DDH values against Thalassotalea species were 68.5-77.0% and 19.7-24.6%, respectively, indicating the novelty of PTE2T. Based on genome-based taxonomic approaches, strain PTE2T (= JCM 34608T = KCTC 82592T) is proposed as a new species, Thalassotalea hakodatensis sp. nov.