Microbial community in a sediment-hosted CO2 lake of the southern Okinawa Trough hydrothermal system

Fumio Inagaki; Marcel M. M. Kuypers; Urumu Tsunogai; Jun-ichiro Ishibashi; Ko-ichi Nakamura; Tina Treude; Satoru Ohkubo; Miwako Nakaseama; Kaul Gena; Hitoshi Chiba; Hisako Hirayama; Takuro Nunoura; Ken Takai; Bo B. Jørgensen; Koki Horikoshi; Antje Boetius

doi:10.1073/pnas.0606083103

New Research In

Communicated by Norman H. Sleep, Stanford University, Stanford, CA, July 21, 2006 (received for review March 10, 2006)

Article Figures & SI

Figures

Download figure

Open in new tab

Download powerpoint

Fig. 1.
Overview of the Yonaguni Knoll IV hydrothermal field at the southern Okinawa Trough. (A) Location map of the Yonaguni Knoll IV. (B) “Lion chimney,” one of the most active black smoker vents in this field. (C) “Crystal chimney,” one of the vapor-rich clear smoker vents adjacent to the Tiger black smoker. The emission of liquid CO₂ droplets was observed in close proximity. (D) White patchy area, “CO₂-hydrate zone,” ≈50 m southward from the Tiger chimney. (E) Continuous emission of liquid CO₂ droplets from the “CO₂ lake” overlying hydrates. White arrows in C and E indicate the emission of liquid CO₂ droplets. The video of these hydrothermal events recorded by DSV Shinkai 6500 is available as Movie 1, which is published as supporting information on the PNAS web site.
Download figure

Open in new tab

Download powerpoint

Fig. 2.
Scheme of the examined sediment sample from the “CO₂-hydrate zone” and related geochemical depth profiles. (A) Location of liquid CO₂/CO₂-hydrate interface, sediment cover, and pavement in core 819NK, and in situ temperatures. (B) Profiles of pH (open diamonds) and alkalinity (as CaCO₃, filled diamonds) in pore waters. (C) Concentrations of SO₄ ²⁻ (filled squares) and Cl⁻ (open squares) in pore water. (D) Concentration of methane and CO₂ in headspace. (E) Carbon isotopic compositions of methane (red circles, t = 0; white circles, t = 14 h) and CO₂ (light blue circles) in headspace. The data from top layer (single points) and sediment column (connected by lines) correspond to 819 pavement and 819NK sediment core, respectively, both obtained from the CO₂-hydrate zone.
Download figure

Open in new tab

Download powerpoint

Fig. 3.
Phylogenetic trees of archaeal (A) and bacterial (B) 16S rRNA gene sequences from the liquid CO₂-hydrate hydrothermal system as marked in red and blue, respectively. The trees were inferred by neighbor-joining analysis by using manually aligned homologous positions of 16S rRNA sequences. The number of related clones with a 97% similarity sequence cutoff are indicated in parentheses. The results of 100 bootstrap trials are shown at each phylogenetic branch. (Scale bars: 0.05-nt substitution per sequence position.)
Download figure

Open in new tab

Download powerpoint

Fig. 4.
Carbon isotopic compositions of archaeal and bacterial lipids extracted from 819p pavements (red) and 819NK core sediments (blue) in the CO₂-hydrate zone and 818 core sediments (black) obtained from outside of the CO₂-hydrate zone (>50 m). Carbon isotopic compositions of CO₂ and methane were obtained from liquid CO₂ droplets collected in situ by the gas-tight sampler. The δ¹³C value of algal organic carbon (OC) was calculated from the δ¹³C value of phytol from core 818, assuming an isotopic offset between phytoplanktonic biomass and phytol of +4‰ (33). Bars indicate SDs (n = 2–6).

Data supplements

Inagaki et al. 10.1073/pnas.0606083103.

Supporting Information
Files in this Data Supplement:
Supporting Figure 5
Supporting Figure 6
Supporting Figure 7
Supporting Figure 8
Supporting Movie 1

Fig. 5. Vertical profiles of temperature measured in situ (A), total sulfur content (B), total cell abundance (C), relative abundance of Archaea (D), clonal frequency of ANME-related archaeal clone sequences (E), and clonal frequency of Deltaproteobacteria sequences. The plotted depths in B–D correspond to sampling depths of core 819NK sediments on board, which has expanded slightly by the effect of phase transition of CO₂ during the recovery.

Fig. 6. Phylogenetic tree of methyl coenzyme M reductase a-subunit genes (mcrA) from liquid CO₂/CO₂-hydrate-bearing sediments at the Yonaguni Knoll IV hydrothermal field. The sequences obtained from the sediments are indicated by red characters. The phylogenetic distance was determined by the neighbor-joining method by using manually aligned nucleic acid sequences. Bootstrap numbers indicate the score of 100 replicates.

Fig. 7. Phylogenetic tree of ribulose 1,5-bisphosphate carboxylase (Rubisco: cbbL) genes from liquid CO₂/CO₂-hydrate-bearing sediments at the Yonaguni Knoll IV hydrothermal field. The sequences obtained from the sediments are indicated by red characters. The phylogenetic distance was determined by the neighbor-joining method by using manually aligned nucleic acid sequences. Bootstrap numbers indicate the score of 100 replicates.

Fig. 8. Concentrations of major lipid components extracted from 819 pavement and core 819NK samples of the CO₂-hydrate zone.

Supporting Movie 1
Movie 1. This movie shows the overview of the Yonaguni Knoll IV hydrothermal field at the southern Okinawa Trough, which was recorded by DSV Shinkai 6500 during the JAMSTEC expeditions YK03-05 and YK04-05. During the course of the movie, one can see the Lion and Tiger black smoker chimneys, the adjacent vapor-rich clear vent fluids from the Crystal chimney with emissions of liquid CO₂ droplets in close proximity, macrofauna assemblages at the foot of the Tiger chimney mound, the white patchy area "CO₂-hydrate zone," and the continuous emission of liquid CO₂ from the sediment-hosted CO₂ lake through the cored borehole (QuickTime).