Thalassotalea litorea sp. nov., isolated from seashore sand

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

Three psychrophilic bacteria, designated as strains SQ149T, SQ345T, and S1-1T, were isolated from deep-sea sediment from the South China Sea. All three strains were the most closely related to Thalassotalea atypica RZG4-3-1T based on the 16S rRNA gene sequence analysis (similarity ranged from 96.45 to 96.67 %). Phylogenetic analysis based on the 16S rRNA gene and core-genome sequences showed that three strains formed a cluster within the genus Thalassotalea. The average amino acid identity, average nucleotide identity, and digital DNA-DNA hybridization values among the three strains and closest Thalassotalea species were far below the cut-off value recommended for delineating species, indicating they each represented a novel species. All three strains were Gram-stain-negative, rod-shaped, and contained summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) as the predominant fatty acid, Q-8 as the major respiratory quinone, and phosphatidylethanolamine and phosphatidylglycerol as predominant polar lipids. Based on the genomic, phylogenetic, and phenotypic characterizations, each strain is considered to represent a novel species within the genus Thalassotalea, for which the names Thalassotalea psychrophila sp. nov. (type strain SQ149T=MCCC 1K04231T=JCM 33807T), Thalassotalea nanhaiensis sp. nov. (type strain SQ345T=MCCC 1K04232T=JCM 33808T), and Thalassotalea fonticola sp. nov. (type strain S1-1T=MCCC 1K06879T=JCM 34824T) are proposed.

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

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 algicola sp. nov., an alginate-utilizing bacterium isolated from a red alga

A facultatively anaerobic bacterium, strain M1531^T, was isolated from a red alga (Porphyra) at coastal water in Weihai, China. Cells of the novel strain were Gram-stain-negative, rod-shaped, motile by means of a single polar flagellum and around 0.6-0.8 × 2.0-3.0 µm in size. Optimum growth occurred at 30 °C, with 2% (w/v) NaCl and at pH 6.5-7.0. On the basis of the result of phylogenetic analysis of the 16S rRNA gene sequence, stain M1531^T had close relative with Thalassotalea euphylliae KCTC 42743^T (96.9%). Genome sequencing revealed a genome size of 4,061,950 bp, a G + C content of 39.1 mol% and four protein-coding genes related to the degradation of alginate. According to the data obtained, strain M1531^T shared ANI value below 95-96%, dDDH value below 23.8% with the closely related type species. Strain M1531^T had Q-8 as the predominant isoprenoid quinone and possessed Summed Features 3 (C_16:1 ω7c/C_16:1 ω6c), C_16:0 and Summed Features 8 (C_18:1 ω7c/C_18:1 ω6c) as the major fatty acids. The polar lipids of strain M1531^T were identified as phosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, one unidentified aminolipid and four unidentified lipids. According to the results of the phenotypic, chemotaxonomic characterization, phylogenetic properties and genome analysis, strain M1531^T represents a novel specie of the genus Thalassotalea, for which the name Thalassotalea algicola sp. nov. is proposed. The type strain is M1531^T (= MCCC 1H00400^T = KCTC 72865^T).

Genomics Reveals the Metabolic Potential and Functions in the Redistribution of Dissolved Organic Matter in Marine Environments of the Genus Thalassotalea

Members of the bacterial genus Thalassotalea have been isolated recently from various marine environments, including marine invertebrates. A metagenomic study of the Deepwater Horizon oil plume has identified genes involved in aromatic hydrocarbon degradation in the Thalassotalea genome, shedding light on its potential role in the degradation of crude oils. However, the genomic traits of the genus are not well-characterized, despite the ability of the species to degrade complex natural compounds, such as agar, gelatin, chitin, or starch. Here, we obtained a complete genome of a new member of the genus, designated PS06, isolated from marine sediments containing dead marine benthic macroalgae. Unexpectedly, strain PS06 was unable to grow using most carbohydrates as sole carbon sources, which is consistent with the finding of few ABC transporters in the PS06 genome. A comparative analysis of 12 Thalassotalea genomes provided insights into their metabolic potential (e.g., microaerobic respiration and carbohydrate utilization) and evolutionary stability [including a low abundance of clustered regularly interspaced short palindromic repeats (CRISPR) loci and prophages]. The diversity and frequency of genes encoding extracellular enzymes for carbohydrate metabolism in the 12 genomes suggest that members of Thalassotalea contribute to nutrient cycling by the redistribution of dissolved organic matter in marine environments. Our study improves our understanding of the ecological and genomic properties of the genus Thalassotalea.

Thalassotalea mangrovi sp. nov., a bacterium isolated from marine mangrove sediment

A novel Gram-stain-negative, strictly aerobic bacterium that has a rod-like shape with a single polar flagellum in the exponential phase of growth and a spherical or ovoid shape without a flagellum in the stationary phase was isolated from a mangrove wetland sediment sample collected at Beilun Estuary National Nature Reserve, Guangxi Province, PR China and designated strain ZS-4^T. This strain grew optimally at pH 6.0-8.0, at a temperature of 37 °C and in the presence of 3-4 % (w/v) NaCl. Its polar lipid profile included phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid and two uncharacterized lipids. Ubiquinone 8 (Q-8) was the sole respiratory quinone and the cellular fatty acids were dominated by C_17 : 1ω8c and C_16 : 0. A phylogenetic analysis based on the 16S rRNA gene sequence showed that strain ZS-4^T exhibited its highest similarities to the type strains Thalassotalea litorea HMF4135^T (97.8 %) and Thalassotalea ponticola GJSW-36^T (95.9 %). A whole genome-level comparison of strain ZS-4^T with T. litorea MCCC 1K03283^T revealed an average nucleotide identity value of 75.6 % and a calculated DNA-DNA hybridization value of 19.6 %. In addition, the genomic DNA G+C content of strain ZS-4^T was 45.9 mol%. Thus, based on analyses of its morphology, physiology, fatty acid composition and 16S rRNA gene sequence, strain ZS-4^T should be considered a novel species of the genus Thalassotalea, with the proposed name Thalassotaleamangrovi sp. nov. The type strain is ZS-4^T (=KCTC 72399^T=MCCC 1K03630^T).

Complete Genome Sequence of Thalassotalea euphylliae Strain H2

A bacterial isolate of Thalassotalea euphylliae H2 was collected from the coral Montipora capitata. MinION long reads were employed for scaffolding and complemented with short-read MiSeq sequences to permit complete genome assembly.

A bacterial isolate of Thalassotalea euphylliae H2 was collected from the coral Montipora capitata. MinION long reads were employed for scaffolding and complemented with short-read MiSeq sequences to permit complete genome assembly. The genome is approximately 4.36 Mb long, with 3,669 protein-coding genes, 92 tRNAs, and 21 rRNAs.

Full-Genome Sequence of Thalassotalea euphylliae H1, Isolated from a Montipora capitata Coral Located in Hawai'i

The isolate of Thalassotalea euphylliae H1 was collected from the surface of a Montipora capitata coral. The genome was assembled using long reads from a Nanopore MinION sequencer for scaffolding and complemented with short-read MiSeq sequences. The genome was approximately 4.77 Mb long with 4,020 protein-coding genes, 92 tRNAs, and 22 rRNAs.

Thalassotalea insulae sp. nov., isolated from tidal flat sediment

A Gram-stain-negative, aerobic, motile and rod-shaped or ovoid bacterial strain, designated JDTF-40^T, was isolated from a tidal flat in Jindo, an island of the Republic of South Korea. Strain JDTF-40^T grew optimally at pH 7.0-8.0, at 30 °C and in the presence of 2 % (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain JDTF-40^T fell within the cluster comprising the type strains of Thalassotalea species. Strain JDTF-40^T exhibited 16S rRNA gene sequence similarity values of 93.8-95.7 % to the type strains of Thalassotalea species. Strain JDTF-40^T contained Q-8 as the predominant ubiquinone and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0 as the major fatty acids. The major polar lipids of strain JDTF-40^T were phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid, one unidentified glycolipid and three unidentified lipids. The DNA G+C content of strain JDTF-40^T was 41.3 mol%. Differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain JDTF-40^T is distinct from recognized species of the genus Thalassotalea. On the basis of the data presented here, strain JDTF-40^T is considered to represent a novel species of the genus Thalassotalea, for which the name Thalassotalea insulae sp. nov. is proposed. The type strain is JDTF-40^T (=KACC 19433^T=KCTC 62186^T=NBRC 113040^T).