Thermophilic bacterial activity in a deep-sea sediment from the Pacific Ocean

A Gram-strain-negative, rod-shaped, aerobic bacterium, designated 216_PA32_1T, was isolated from deep-sea sediment of the Pacific Ocean. Cells of strain 216_PA32_1T were non-motile, oxidase-positive and catalase-negative. The strain could grow at temperatures of 10–45 °C (optimum, 32–35 °C), at pH 5.0–10.0 (optimum, 6.0–7.0) and at salinities of 0–10% (optimum, 2–8%). The principal fatty acid (>10 %) was summed feature 8 (C18:1 ω6c/ω7c). The sole respiratory quinone was Q10 (100 %). The polar lipids included phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, phosphatidylmonomethylethanolamine, two unidentified phospholipids and five unidentified aminolipids. The G+C content of the chromosomal DNA was 66.3 mol%. According to the 16S rRNA gene similarity, strain 216_PA32_1T showed the highest sequence similarity to Pseudooceanicola nitratireducens JLT 1210T (97.3 %), followed by Pseudooceanicola nanhaiensis SS011B1-20T (97.1 %). Phylogenetic trees indicated that strain 216_PA32_1T clustered with strain P. nanhaiensis SS011B1-20T. The average nucleotide identity and the DNA–DNA hybridization values between strain 216_PA32_1T and all species of the genus Pseudooceanicola were below 79.5 and 20.6%, respectively. A combination of the phylogenetic, phenotypic, chemotaxonomic and genomic evidence demonstrated that strain 216_PA32_1T represents a novel species of the genus Pseudooceanicola , for which the name Pseudooceanicola pacificus sp. nov. is proposed. The type strain is 216_PA32_1T (=MCCC 1A14128T=KCTC 72688T).

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Halomonas diversa sp. nov., isolated from deep-sea sediment of the Pacific Ocean

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijsem.0.004790 ◽

2021 ◽

Vol 71 (4) ◽

Author(s):

Liping Wang ◽

Xiupian Liu ◽

Qiliang Lai ◽

Li Gu ◽

Zongze Shao

Keyword(s):

Pacific Ocean ◽

16S Rrna ◽

Deep Sea ◽

Type Species ◽

Sequence Similarity ◽

Content Type ◽

Deep Sea Sediment ◽

Link Type ◽

The Pacific ◽

The Pacific Ocean

A novel Gram-stain-negative, facultatively anaerobic, rod-shaped bacterium, designated as D167-6-1T, was isolated from deep-sea sediment collected from the Pacific Ocean. The cells were catalase- and oxidase-positive, and motile by means of peritrichous flagella. Growth occurred at NaCl concentrations ranging from 0 to 19 % (optimum, 2–8 %, w/v), from pH 6 to 11 (optimum, 7–8) and at temperatures between 4 and 45 °C (optimum, 33 °C). Phylogenetic analysis based on 16S rRNA, gyrB and rpoD gene sequences and its genome sequence revealed that strain D167-6-1T formed a monophyletic branch within the genus Halomonas and was most closely related to Halomonas saliphila , Halomonas pellis , Halomonas kenyensis , Halomonas daqingensis , Halomonas desiderata and Halomonas lactosivorans (with 98.5, 98.5, 98.4, 98.1, 97.5 and 97.8 % 16S rRNA sequence similarity, respectively). The complete genome size of strain D167-6-1T was 4.49 Mb, with a DNA G+C content of 62.8 mol%. The estimated averagenucleotide identity and DNA–DNA hybridization values between strain D167-6-1T and other closely related species were 77.59–85.35 % and 22.0–30.6 %, respectively. The principal cellular fatty acids (>5 %) were C18 : 1 ω7c, C16 : 0, C19 : 0 cyclo ω8c, summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c) and C17 : 0 cyclo. The polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, an unidentified aminolipid, aminophospholipid and two unidentified phospholipids. The predominant respiratory quinones were Q-9 and Q-8. The combined genotypic and phenotypic data show that strain D167-6-1T represents a novel species of the genus Halomonas , for which the name Halomonas diversa sp. nov. is proposed, with the type strain D167-6-1T (=MCCC 1A13316T=KCTC 72441T).

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A biogeographic network reveals evolutionary links between deep-sea hydrothermal vent and methane seep faunas

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2016.2337 ◽

2016 ◽

Vol 283 (1844) ◽

pp. 20162337 ◽

Cited By ~ 19

Author(s):

Steffen Kiel

Keyword(s):

Pacific Ocean ◽

Deep Sea ◽

Hydrothermal Vents ◽

Subduction Zones ◽

Continental Margins ◽

Stepping Stones ◽

The Pacific ◽

The Pacific Ocean ◽

Active Continental Margins ◽

Ocean Ridge

Deep-sea hydrothermal vents and methane seeps are inhabited by members of the same higher taxa but share few species, thus scientists have long sought habitats or regions of intermediate character that would facilitate connectivity among these habitats. Here, a network analysis of 79 vent, seep, and whale-fall communities with 121 genus-level taxa identified sedimented vents as a main intermediate link between the two types of ecosystems. Sedimented vents share hot, metal-rich fluids with mid-ocean ridge-type vents and soft sediment with seeps. Such sites are common along the active continental margins of the Pacific Ocean, facilitating connectivity among vent/seep faunas in this region. By contrast, sedimented vents are rare in the Atlantic Ocean, offering an explanation for the greater distinction between its vent and seep faunas compared with those of the Pacific Ocean. The distribution of subduction zones and associated back-arc basins, where sedimented vents are common, likely plays a major role in the evolutionary and biogeographic connectivity of vent and seep faunas. The hypothesis that decaying whale carcasses are dispersal stepping stones linking these environments is not supported.

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