著者

Takuro Nunoura Manabu Nishizawa Miho Hirai Shigeru Shimamura Phurt Harnvoravongchai Osamu Koide Yuki Morono Toshiaki Fukui Fumio Inagaki Junichi Miyazaki Yoshihiro Takaki Ken Takai

出版者

Japanese Society of Microbial Ecology · The Japanese Society of Soil Microbiology

雑誌

Microbes and Environments (ISSN:13426311)

巻号頁・発行日

vol.33, no.2, pp.186-194, 2018 (Released:2018-07-04)

参考文献数

72

被引用文献数

67

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The Challenger Deep is the deepest ocean on Earth. The present study investigated microbial community structures and geochemical cycles associated with the trench bottom sediments of the Challenger Deep, the Mariana Trench. The SSU rRNA gene communities found in trench bottom sediments were dominated by the bacteria Chloroflexi (SAR202 and other lineages), Bacteroidetes, Planctomycetes, “Ca. Marinimicrobia” (SAR406), and Gemmatimonadetes and by the archaeal α subgroup of MGI Thaumarchaeota and “Ca. Woesearchaeota” (Deep-sea Hydrothermal Vent Euryarchaeotic Group 6). The SSU rRNA gene sequencing analysis indicated that the dominant populations of the thaumarchaeal α group in hadal water and sediments were similar to each other at the species or genus level. In addition, the co-occurrence of nitrification and denitrification was revealed by the combination of pore water geochemical analyses and quantitative PCR for nitrifiers.

著者

JUN-ICHIRO ISHIBASHI TAKUROH NOGUCHI TOMOHIRO TOKI SHUNSUKE MIYABE SHOSEI YAMAGAMI YUJI ONISHI TOSHIRO YAMANAKA YUKA YOKOYAMA ERIKO OMORI YOSHIO TAKAHASHI KENTA HATADA YUZURU NAKAGUCHI MOTOKO YOSHIZAKI UTA KONNO TAKAZO SHIBUYA KEN TAKAI FUMIO INAGAKI SHINSUKE KAWAGUCCI

出版者

GEOCHEMICAL SOCIETY OF JAPAN

雑誌

GEOCHEMICAL JOURNAL (ISSN:00167002)

巻号頁・発行日

vol.48, no.4, pp.357-369, 2014-07-20 (Released:2014-07-31)

参考文献数

48

被引用文献数

23 67

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Two active hydrothermal fields, Jade and Hakurei fields have been discovered within the Izena Hole, a rectangular 6 km × 3 km shape depression located in the middle Okinawa Trough back arc basin. In both fields, intense hydrothermal activity is represented by venting of high-temperature fluid (>300°C) and occurrence of sulfide/sulfate ore deposits. We collected hydrothermal fluids during dive expeditions of ROV Hyper Dolphin conducted in 2003, 2010 and 2011, in order to analyze both elemental and gas species. The geochemistry of high temperature hydrothermal fluids collected from the Jade and Hakurei fields is very similar to each other with exceptions in minor gas composition. Little temporal variation was observed in geochemistry of the high-temperature hydrothermal fluid of the Jade field over two decades, since a previous study carried out in 1989. These results suggest that these fluids are derived from a common fluid reservoir where fluid chemistry is basically controlled by fluid-mineral equilibria and gas species are dominantly contributed from the same magma. Venting of low temperature fluid (about 104°C) was discovered in the distal part of the Jade field, which was named as the Biwako vent. Chemical composition of the Biwako vent fluid was distinctive from that of the high temperature fluid in the proximal part of the Jade field, and could not be explained by simple dilution or cooling. This intra-field chemical diversity could be caused by phase separation and segregation during fluid upwelling, based on relationships in concentrations of Cl and major cations. On the other hand, the chemical diversity recognized in minor gas composition between the Jade and Hakurei fields is in accordance with results from previous plume survey. Difference in concentrations of minor gases such as H2 is attributed to contribution from thermal degradation of organic matter in the sediment, during fluid upwelling.

著者

Fumio Inagaki Yoshinobu Motomura Katsumi Doi Sachihiro Taguchi Eiji Izawa Donald R. Lowe Seiya Ogata

出版者

Japanese Society of Microbial Ecology · The Japanese Society of Soil Microbiology

雑誌

Microbes and Environments (ISSN:13426311)

巻号頁・発行日

vol.16, no.2, pp.125-130, 2001 (Released:2001-07-16)

参考文献数

32

被引用文献数

16 29

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At Steep Cone hot spring, Lower Geyser Basin, Yellowstone National Park, a mound of siliceous deposits called "siliceous sinter" forms from discharged boiling geothermal water that is supersaturated with amorphous silica. Electron-probe microanalyzer (EPMA) observations suggested that silica is deposited on the surface of the cells and that microorganisms affect the formation of the siliceous sinter. EPMA signals and backscattered electron images of sinter samples taken at the inner wall of the boiling pool revealed framboidal pyrite structures associated with a network of silicified microbial structures. The structure of bacterial community in a beige-colored sinter sediment (75.8°C, pH 8.6) was studied by molecular clone type phylogenetic analysis of PCR-mediated 16S rDNA fragments. The bacterial rDNA clones found indicated the presence of a complex community in the sinter sediment. Sequences closely related to the genera Thermus and Saccharomonospora were dominated; evidence of indigenous microbial components.

著者

Takuro Nunoura Manabu Nishizawa Miho Hirai Shigeru Shimamura Phurt Harnvoravongchai Osamu Koide Yuki Morono Toshiaki Fukui Fumio Inagaki Junichi Miyazaki Yoshihiro Takaki Ken Takai

出版者

Japanese Society of Microbial Ecology · The Japanese Society of Soil Microbiology

雑誌

Microbes and Environments (ISSN:13426311)

巻号頁・発行日

pp.ME17194, (Released:2018-05-25)

被引用文献数

67

---

The Challenger Deep is the deepest ocean on Earth. The present study investigated microbial community structures and geochemical cycles associated with the trench bottom sediments of the Challenger Deep, the Mariana Trench. The SSU rRNA gene communities found in trench bottom sediments were dominated by the bacteria Chloroflexi (SAR202 and other lineages), Bacteroidetes, Planctomycetes, “Ca. Marinimicrobia” (SAR406), and Gemmatimonadetes and by the archaeal α subgroup of MGI Thaumarchaeota and “Ca. Woesearchaeota” (Deep-sea Hydrothermal Vent Euryarchaeotic Group 6). The SSU rRNA gene sequencing analysis indicated that the dominant populations of the thaumarchaeal α group in hadal water and sediments were similar to each other at the species or genus level. In addition, the co-occurrence of nitrification and denitrification was revealed by the combination of pore water geochemical analyses and quantitative PCR for nitrifiers.