Late Miocene‐Pliocene Vigorous Deep‐Sea Circulation in the Southeast Indian Ocean: Paleoceanographic and Tectonic Implications

A taxonomic study was carried out on strain CIC4N-9T, which was isolated from deep-sea water of the Indian Ocean. The bacterium was Gram-stain-negative, catalase- and oxidase-positive, rod-shaped and non-motile. Growth was observed at salinities of 0–9% and at temperatures of 4–41 °C. The isolate was able to degrade gelatin but not aesculin. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CIC4N-9T belonged to the genus Pararhodobacter , with the highest sequence similarity to the only recognized species, Pararhodobacter aggregans D1-19T (96.9 %). The average nucleotide identity and estimated DNA–DNA hybridization values between strain CIC4N-9T and P. aggregans D1-19T were 80.4 and 23.0 %, respectively. The principal fatty acids were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), C16 : 0, C18 : 1ω7c 11-methyl, C18 : 0 and C17 : 0. The G+C content of the chromosomal DNA was 66.8 mol%. The sole respiratory quinone was determined to be Q-10. Phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, two unknown phospholipids, four unknown aminolipids and one unknown polar lipid were present. The combined genotypic and phenotypic data show that strain CIC4N-9T represents a novel species within the genus Pararhodobacter , for which the name Pararhodobacter marinus sp. nov. is proposed. The type strain is CIC4N-9T (=MCCC 1A01225T=KCTC 52336T).

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Seismic profiles of the eastern Indian Ocean and deep-sea drilling

Geoexploration ◽

10.1016/0016-7142(74)90052-0 ◽

1974 ◽

Vol 12 (2-3) ◽

pp. 207

Author(s):

J.J. Veevers

Keyword(s):

Indian Ocean ◽

Deep Sea ◽

Eastern Indian Ocean ◽

Seismic Profiles

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Sulfurovum indicum sp. nov., a novel hydrogen- and sulfur-oxidizing chemolithoautotroph isolated from a deep-sea hydrothermal plume in the Northwestern Indian Ocean

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijsem.0.004748 ◽

2019 ◽

Vol 71 (3) ◽

Cited By ~ 4

Author(s):

Shaobin Xie ◽

Shasha Wang ◽

Dengfeng Li ◽

Zongze Shao ◽

Qiliang Lai ◽

...

Keyword(s):

Indian Ocean ◽

Deep Sea ◽

Type Species ◽

Elemental Sulfur ◽

Sequence Similarity ◽

Rrna Gene ◽

Phenotypic Data ◽

Content Type ◽

Link Type ◽

Sulfur Oxidizing

A novel mesophilic, hydrogen-, and sulfur-oxidizing bacterium, designated strain ST-419T, was isolated from a deep-sea hydrothermal vent plume on the Carlsberg Ridge of the Northwestern Indian Ocean. The isolate was a Gram-staining-negative, non-motile and coccoid to oval-shaped bacterium. Growth was observed at 4–50 °C (optimum 37 °C), pH 5.0–8.6 (optimum pH 6.0) and 1.0–5.0 % (w/v) NaCl (optimum 3.0 %). ST-419T could grow chemlithoautotrophically with molecular hydrogen, sulfide, elemental sulfur and thiosulfate as energy sources. Molecular oxygen, nitrate and elemental sulfur could be used as electron acceptors. The predominant fatty acids were C16 : 1ω7c, C18 : 1ω7c and C16 : 0. The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The respiratory quinone was menaquinone MK-6 and the G+C content of the genomic DNA was 42.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that ST-419T represented a member of genus Sulfurovum and was most closely related to Sulfurovum riftiae 1812ET, with 97.6 % sequence similarity. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between ST-419T and S. riftiae 1812ET were 74.6 and 19.6 %, respectively. The combined genotypic and phenotypic data indicate that ST-419T represents a novel species within the genus Sulfurovum , for which the name Sulfurovum indicum sp. nov. is proposed. The type strain is ST-419T (=MCCC 1A17954T=KCTC 25164T).

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Deep-sea panoramas: Progress and remaining challenges in late Miocene stratigraphy and climate

10.5194/egusphere-egu21-11904 ◽

2021 ◽

Author(s):

Anna Joy Drury ◽

Thomas Westerhold ◽

David A. Hodell ◽

Mitchell Lyle ◽

Cédric M. John ◽

...

Keyword(s):

High Resolution ◽

Ocean Circulation ◽

Late Miocene ◽

Deep Sea ◽

Deep Ocean ◽

High Resolution Data ◽

Ongoing Work ◽

Climate Evolution ◽

Deep Ocean Circulation ◽

Geological Timescale

During the late Miocene, meridional sea surface temperature gradients, deep ocean circulation patterns, and continental configurations evolved to a state similar to modern day. Deep-sea benthic foraminiferal stable oxygen (&#948;18O) and carbon (&#948;13C) isotope stratigraphy remains a fundamental tool for providing accurate chronologies and global correlations, both of which can be used to assess late Miocene climate dynamics. Until recently, late Miocene benthic &#948;18O and &#948;13C stratigraphies remained poorly constrained, due to relatively poor global high-resolution data coverage.Here, I present ongoing work that uses high-resolution deep-sea foraminiferal stable isotope records to improve late Miocene (chrono)stratigraphy. Although challenges remain, the coverage of late Miocene benthic &#948;18O and &#948;13C stratigraphies has drastically improved in recent years, with high-resolution records now available across the Atlantic and Pacific Oceans. The recovery of these deep-sea records, including the first astronomically tuned, deep-sea integrated magneto-chemostratigraphy, has also helped to improve the late Miocene geological timescale. Finally, I will briefly touch upon how our understanding of late Miocene climate evolution has improved, based on the high-resolution deep-sea archives that are now available.

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