2021 Fiscal Year Annual Research Report
Insights into hydrocarbons cycling in the subsurface from isotopologue analysis
| Project/Area Number |
21H01198
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
ジルベルト アレキシー 東京工業大学, 理学院, 准教授 (20726955)
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| Co-Investigator(Kenkyū-buntansha) |
中川 麻悠子 東京工業大学, 地球生命研究所, 特任助教 (20647664)
山田 桂太 東京工業大学, 物質理工学院, 准教授 (70323780)
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| Project Period (FY) |
2021-04-01 – 2024-03-31
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| Keywords | Hydrocarbons / Carbon cycle / Subsurface / Isotopologue |
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| Outline of Annual Research Achievements |
We sampled at Goshogake mud volcano (Akita prefecture). The geological setting is a mix between sedimentary and volcanic mud volcano. Unfortunately, after analysis we found that the gas contained mainly CO2 (99%) and very few methane or other hydrocarbons. We decided to give up studying this setting given that the goal of the project is to study hydrocarbons cycling.
In parallel, we went sampling in Tokamachi (Niigata prefecture) and analyzed isotpologue of hydrocarbons, the results of which will appear in a paper to be submitted.
We also started incubation experiments using the mud from Tokamachi and diverse substrates. We could grow microorganisms using different substrates: acetate, CO2 + H2 and hexadecane.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
We tried to sample at Goshogake, a mud volcano in Akita prefecture.
Unfortunately, the sampling appeared difficult, and the only samples that we could measure show high CO2 amounts and low methane amounts, which suggest this setting is not related to hydrocarbons generation.
We therefore decided to focus on Tokamachi mud volcano and take advantage of the numerous gas seeps present to build a quantitative model of hydrocarbon cycling using this setting as a model
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| Strategy for Future Research Activity |
We will continue culture experiments, with. a particular focus on methanogens which are allegedly responsible for the high 13C/12C CO2 in biodegraded oil reservoirs. Other microorganisms will also be investigated, notably hexadecane which allows simulating oil biodegradation.
We will focus on Tokamachi mud volcano since it provides several sampling points with different levels of biodegradation. This will allow us to build a quantitative model of C-cycling in hydrocarbons-based ecosystems.
We will also explore the isotopologue signatures of methane, ethane and propane and how they are affected by biodegradation.
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