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.

Thalassotalea psychrophila sp. nov., Thalassotalea nanhaiensis sp. nov. and Thalassotalea fonticola sp. nov., three psychrophilic bacteria isolated from deep-sea sediment

“…Based on the genomic similarity indices, all three strains were members of the genus Thalassotalea and they each represented a novel species. It was noted that the three isolates shared even lower ANI and AAI values with four Thalassotalea strains (T. hakodatensis, T. marina, T. loyana, and T. euphylliae) than with some species from Thalassomonas, Colwellia, Litorilituus, and Cognaticolwellia, which was similar to the phenomenon observed earlier with T. hakodatensis [11].…”

“…Sixteen complete or nearly complete genomes of type strains from Thalassotalea are now available from the NCBI [11]. A recent phylogenomic analysis showed that the in silico DNA–DNA hybridization (DDH) and average nucleotide identity (ANI) values between certain Thalassotalea species are even lower than with species from other genera from the family Colwelliaceae , such as Colwellia , Litorilituus , and Thalassomonas [11]. In addition, multiple monophyletic clades have been observed within the genera Thalassotalea and Colwellia .…”

“…Collectively, the data suggests that further examinations of the taxonomy of the family Colwelliaceae are necessary. All currently described members of the genus Thalassotalea were isolated from surface or shallow marine environments such as marine sediment [7,9,12,13], seawater [3,4,6,14,15], marine animals [1,5,8,11,[16][17][18][19], and sea sand [2,20]. In this study, three strains (SQ149 T , SQ345 T , and S1-1 T ) were isolated from deep-sea sediment collected at depths of over 1000 m in the South China Sea.…”

Genomic Insights into the Symbiotic and Plant Growth-Promoting Traits of “Candidatus Phyllobacterium onerii” sp. nov. Isolated from Endemic Astragalus flavescens

“…The fatty acid metabolism pathway based on KEGG is illustrated in Figure 6 . This pathway is responsible for synthesizing three major fatty acids: C16:0, C16:1, and C18:1 [ 47 ]. The genome of strain IY22 encodes fabA and fabB, indicating the potential to produce C16:1ω7c and C18:1ω7c.…”

Genome taxonomy of the genus Neptuniibacter and proposal of Neptuniibacter victor sp. nov. isolated from sea cucumber larvae

“…Overall genome relatedness indices (OGRIs) were calculated to determine the novelty of PT1 T using same approach by Yamano et al [ 5 , 6 ]. Average nucleotide identities (ANIs) were calculated using the Orthologous Average Nucleotide Identity Tool (OrthoANI) software ver.…”