Study on the mechanisms of biogenic basalt alteration by synchrotron-based X-ray microscopy

• Project/Area Number: 15H05330
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Environmental dynamic analysis
• Research Institution: Ehime University
• Principal Investigator: Mitsunobu Satoshi 愛媛大学, 農学研究科, 准教授 (70537951)
• Research Collaborator: Makita Hiroko
• Project Period (FY): 2015-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥18,850,000 (Direct Cost: ¥14,500,000、Indirect Cost: ¥4,350,000); Fiscal Year 2018: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2017: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2016: ¥6,890,000 (Direct Cost: ¥5,300,000、Indirect Cost: ¥1,590,000); Fiscal Year 2015: ¥7,800,000 (Direct Cost: ¥6,000,000、Indirect Cost: ¥1,800,000)
• Keywords: 海洋地殻 / 生物的風化 / XAFS / 鉄酸化反応 / バクテリア / 風化 / 微生物 / X線顕微鏡 / STXM / スペシエーション / 走査型透過X線顕微鏡 / バイオミネラル / 物質循環 / 鉄 / 玄武岩 / パイライト

Outline of Final Research Achievements

The weathering of oceanic basalt has a significant impact on Earth's climate on a geological timescale by providing a sink for atmospheric CO2 through carbonization of oceanic basalts. The fresh basalt rock contains abundant Fe and its major species is Fe(II). Recent previous studies have reported that oceanic microorganisms would play a significant role to the oxidation of Fe(II) in the basalt. In this study, we investigated the mechanisms of the biogenic Fe(II) oxidation in basalt weathering by synchrotron X-ray spectrocopic techniques. We appliyed the techniques into the basalt samples prepared by in situ incubation of fresh basalt at deep seafloor in Izu-Ogasawara bonin. Our analysis of the sample clearly showed that microbial Fe(II) oxidation is more rapid reaction than abiotic Fe(II) oxidation and that the biotic Fe(II) oxidation promotes the whole basalt weathering. These findings would be an important knowledge to understand mechanism of biogenic weathering of oceanic crust.

Academic Significance and Societal Importance of the Research Achievements

上述の通り、海洋地殻である玄武岩の酸化風化は海洋のCO2固定を促進するため、地球規模の炭素循環を考える上でも重要な反応である。本研究では、ナノスケールの空間分解能を有する先端的X線顕微鏡を利用して、鉱物－微生物細胞界面における鉄、酸素、炭素の元素分布さらには化学種分析をおこない、海底下微生物が玄武岩風化を促進させる分子レベルでの証拠を得た。これらの知見は、地球規模の炭素循環に果たす海底下微生物の影響を再考するきわめて重要な知見となる。

Research Products

• [Journal Article] Significant contribution of subseafloor microparticles to the global (2019)
  • Author(s): Uramoto Go-Ichiro, Morono Yuki, Tomioka Naotaka, Wakaki Shigeyuki, Nakada Ryoichi, Wagai Rota, Uesugi Kentaro, Takeuchi Akihisa, Hoshino Masato, Suzuki Yoshio,Shiraishi Fumito, Mitsunobu Satoshi, Suga Hiroki, Takeichi Yasuo, Takahashi Yoshio,Inagaki Fumio
  • Journal Title: Nature Communications Volume: 10 Pages: 400-400
  • Peer Reviewed
• [Journal Article] μXAFS and TEM studies of Fe(III) oxides precipitated on submarine basaltic (2018)
  • Author(s): Satoshi Mitsunobu, Yohey Suzuki, Katsuaki Watanabe, Kiho Yang, Jin-Wook Kim
  • Journal Title: Chemical Geology Volume: 501 Pages: 51-57
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Spatially resolved distribution of fe species around microbes at the submicron scale in natural bacteriogenic iron oxides. (2017)
  • Author(s): Suga, H, Kikuchi, S, Takeichi, Y, Miyamoto, C, Miyahara, M, Mitsunobu, S, Ohigashi, T, Mase, K, Ono, K, Takahashi, Y
  • Journal Title: Microbes & Environments Volume: 32 Pages: 283-287
  • NAID: 130006105328
  • Peer Reviewed
• [Journal Article] Direct detection of Fe(II) in extracellular polymeric substances (EPS) at the mineral-microbe interface in bacterial pyrite leaching (2016)
  • Author(s): Mitsunobu S, Zhu M, Takeichi Y, Ohigashi T, Suga H, Makita H, Sakata M, Ono K, Mase K, Takahashi Y
  • Journal Title: Microbes & Environments Volume: 31 Pages: 63-69
  • NAID: 130005138797
  • Peer Reviewed
• [Journal Article] Comparative analysis of microbial communities in iron-dominated flocculent mats in deep-sea hydrothermal environments (2016)
  • Author(s): Makita H, Kikuchi S, Mitsunobu S, Takaki Y, Yamanaka T, Toki T, Noguchi T, Nakamura K, Abe M, Hirai M, Yamamoto M, Uematsu K, Miyazaki J, Nunoura T, Takahashi Y, Takai K
  • Journal Title: Applied & Environmental Microbiology Volume: 82 Pages: 5741-5755
  • NAID: 120006383301
  • Peer Reviewed
• [Journal Article] 走査型透過X 線顕微鏡を用いて環境試料中の有機物を調べることの重要性 (2016)
  • Author(s): 光延 聖，菅大暉，高橋嘉夫
  • Journal Title: 放射光 Volume: 29 Pages: 294-302
  • Peer Reviewed
• [Journal Article] Direct Detection of Fe(II) in Extracellular Polymeric Substances (EPS) at the Mineral-Microbe Interface in Bacterial Pyrite Leaching (2016)
  • Author(s): Mitsunobu S., Zhu M., Takeichi Y., Ohigashi T., Suga H., Jinno M., Makita H., Sakata M., Ono K., Mase K., Takahashi Y.
  • Journal Title: Microbes and Environments Volume: 31 Issue: 1 Pages: 63-69
  • DOI: 10.1264/jsme2.ME15137
  • NAID: 130005138797
  • ISSN: 1342-6311, 1347-4405
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] 放射光源X線顕微鏡をもちいた環境中の微生物－元素－鉱物相互作用の直接観察 (2017)
  • Author(s): 光延聖
  • Organizer: 日本バイオイメージング学会
  • Invited
• [Presentation] 深海底での微生物現場培養実験から紐解く鉄を基盤とした海底下微生物圏－放射光源X線分析法を駆使した微生物による地殻内エネルギー獲得戦略の解明－ (2016)
  • Author(s): 大橋 優莉, 光延 聖, 坂田 昌弘, 鈴木 優美, 牧田 寛子, 野崎 達生, 川口 慎介
  • Organizer: 2016年度日本微生物生態学会年会
  • Place of Presentation: 横須賀市文化会館（神奈川県横須賀市）
  • Year and Date: 2016-10-22
• [Presentation] X線顕微鏡で微生物－金属－鉱物反応を観る－放射光源X線顕微鏡を駆使した分子環境地球化学－ (2016)
  • Author(s): 光延聖
  • Organizer: 2016年日本土壌肥料学会年会
  • Place of Presentation: 佐賀大学（佐賀県佐賀市）
  • Year and Date: 2016-09-20
  • Invited
• [Presentation] 放射光源X線吸収分光法による分子スケールスペシエーションを駆使した微生物－鉄－鉱物（岩石）相互作用研究 (2015)
  • Author(s): 光延 聖
  • Organizer: 2015年日本地球化学会年会
  • Place of Presentation: 横浜国立大学（横浜市）
  • Year and Date: 2015-09-16
• [Presentation] 深海底での微生物現場培養実験から紐解く鉄を基盤とした海底下微生物圏： 放射光源X線分析法を駆使した微生物による地殻内エネルギー獲得戦略の解明 (2015)
  • Author(s): 大橋優莉, 光延 聖, 坂田昌弘, 鈴木優美, 牧田寛子, 野崎達生, 川口慎介
  • Organizer: 2015年日本地球化学会年会
  • Place of Presentation: 横浜国立大学（横浜市）
  • Year and Date: 2015-09-16