Researcher Information
researchmap URL
Research Interests
Research History
- Apr. 2026 - Present
Japan Agency for Marine-Earth Science and Technology, Institute for Earth and Material Sciences, Biogeochemistry Research Center, Scientist - Oct. 2023 - Mar. 2026
Japan Agency for Marine-Earth Science and Technology, Research Institute for Marine Resources Utilization, Biogeochemistry Research Center, 副主任研究員 - Oct. 2018 - Sep. 2023
Japan Agency for Marine-Earth Science and Technology, Research Institute for Marine Resources Utilization, Biogeochemistry Research Center, 研究員 - Apr. 2018 - Sep. 2018
Japan Agency for Marine-Earth Science and Technology, 生物地球化学研究分野, 日本学術振興会特別研究員（PD） - Apr. 2016 - Mar. 2018
The University of Tokyo, Atmosphere and Ocean Research Institute, 日本学術振興会特別研究員（DC2）
Research activity information
Papers
- Masanori Kaneko; Yoshinori Takano; Yuta Isaji; Nanako O. Ogawa; Yoshito Chikaraishi; Naoto F. Ishikawa; Hiroyuki Imachi; Yoshihiro Takaki; Miyuki Ogawara; Fumie Kabashima; Martin Krüger; Naohiko Ohkouchi
Nitrogen and carbon flows in a microbial mat involving anaerobic oxidation of methane in northwestern Black Sea: perspectives from nitrogen and carbon isotopic composition of coenzyme F430 and its biosynthetic pathway
Progress in Earth and Planetary Science, 06 Dec. 2025 - Aymeric P. M. Servettaz; Yuta Isaji; Chisato Yoshikawa; Yanghee Jang; Boo-Keun Khim; Yeongjun Ryu; Daniel M. Sigman; Nanako O. Ogawa; Francisco J. Jiménez-Espejo; Naohiko Ohkouchi
Sea ice and mixed layer depth influence on nitrate depletion and associated isotopic effects in the Drake Passage–Weddell Sea region, Southern Ocean
Biogeosciences, 13 May 2025 - Toshihiro Yoshimura; Naoto F. Ishikawa; Nanako O. Ogawa; Soichiro Kusaka; Shigeyuki Wakaki; Tsuyoshi Ishikawa; Kazuya Nagaishi; Masanori Kaneko; Yuta Isaji; Yoshito Chikaraishi; Naohiko Ohkouchi
Magnesium isotopic variation in marine fish organs
Progress in Earth and Planetary Science, 06 Mar. 2025 - Yuta Isaji; Koji Sugie; Naoto F. Ishikawa; Nanako O. Ogawa; Kazuhiko Matsumoto; Chisato Yoshikawa; Hajime Obata; Makio C. Honda; Naohiko Ohkouchi
Distributions of heme B and its implications on Fe biogeochemistry in the eastern Indian Ocean and the western North Pacific Ocean
Progress in Earth and Planetary Science, 11 Feb. 2025 - Yuchen Sun; Thomas M. Blattmann; Yoshinori Takano; Nanako O. Ogawa; Yuta Isaji; Naoto F. Ishikawa; Naohiko Ohkouchi
Enantiomer-Specific Stable Carbon and Nitrogen Isotopic Analyses of Underivatized Individual L- and D-Amino Acids by HPLC + HPLC Separation and Nano-EA/IRMS
Analytical Chemistry, 26 Nov. 2024 - Ohkouchi, N.; Isaji, Y.; Ogawa, N.O.
Regulation of nitrogen isotopic ratios of cellular components
Progress in Earth and Planetary Science, 2024
11, 1 - Kajita, H.; Isaji, Y.; Kato, R.; Nishikura, Y.; Murayama, M.; Ohkouchi, N.; Yang, S.; Zheng, H.; Wang, K.; Nakanishi, T.; Sasaki, T.; Maeda, A.; Suzuki, A.; Yamanaka, T.; Kawahata, H.
Climatic change around the 4.2 ka event in coastal areas of the East China Sea and its potential influence on prehistoric Japanese people
Palaeogeography, Palaeoclimatology, Palaeoecology, 2023
609 - Yuta Isaji; C. Yoshikawa; N. O. Ogawa; K. Matsumoto; A. Makabe; S. Toyoda; N. F. Ishikawa; H. Ogawa; H. Saito; M. C. Honda; N. Ohkouchi
Nitrogen Sources for Phytoplankton in the Eastern Indian Ocean Determined From δ15N of Chlorophyll a and Divinylchlorophyll a
Geochemistry, Geophysics, Geosystems, Apr. 2022
23, 4 - Isaji, Y.; Ogawa, N.O.; Boreham, C.J.; Kashiyama, Y.; Ohkouchi, N.
Evaluation of δ13C and δ15N Uncertainties Associated with the Compound-Specific Isotope Analysis of Geoporphyrins
Analytical Chemistry, 2020
92, 4 - Isaji, Y.; Ogawa, N.O.; Takano, Y.; Ohkouchi, N.
Quantification and carbon and nitrogen isotopic measurements of heme B in environmental samples
Analytical Chemistry, 2020
92, 16 - Isaji, Y.; Kawahata, H.; Takano, Y.; Ogawa, N.O.; Kuroda, J.; Yoshimura, T.; Lugli, S.; Manzi, V.; Roveri, M.; Ohkouchi, N.
Diazotrophy drives primary production in the organic-rich shales deposited under a stratified environment during the messinian salinity crisis (Vena Del Gesso, Italy)
Frontiers in Earth Science, 2019
7 - Isaji, Y.; Kawahata, H.; Ogawa, N.O.; Kuroda, J.; Yoshimura, T.; Jim{\'e}nez-Espejo, F.J.; Makabe, A.; Shibuya, T.; Lugli, S.; Santulli, A.; Manzi, V.; Roveri, M.; Ohkouchi, N.
Efficient recycling of nutrients in modern and past hypersaline environments
Scientific Reports, 2019
9, 1 - Isaji, Y.; Yoshimura, T.; Araoka, D.; Kuroda, J.; Ogawa, N.O.; Kawahata, H.; Ohkouchi, N.
Magnesium Isotope Fractionation during Synthesis of Chlorophyll a and Bacteriochlorophyll a of Benthic Phototrophs in Hypersaline Environments
ACS Earth and Space Chemistry, 2019
3, 6 - Isaji, Y.; Yoshimura, T.; Kuroda, J.; Tamenori, Y.; Jim{\'e}nez-Espejo, F.J.; Lugli, S.; Manzi, V.; Roveri, M.; Kawahata, H.; Ohkouchi, N.
Biomarker records and mineral compositions of the Messinian halite and K–Mg salts from Sicily
Progress in Earth and Planetary Science, 2019
6, 1 - Isaji, Y.; Kawahata, H.; Kuroda, J.; Yoshimura, T.; Ogawa, N.O.; Suzuki, A.; Shibuya, T.; Jim{\'e}nez-Espejo, F.J.; Lugli, S.; Santulli, A.; Manzi, V.; Roveri, M.; Ohkouchi, N.
Biological and physical modification of carbonate system parameters along the salinity gradient in shallow hypersaline solar salterns in Trapani, Italy
Geochimica et Cosmochimica Acta, 2017
208 - Yoshimura, T.; Kuroda, J.; Lugli, S.; Tamenori, Y.; Ogawa, N.O.; Jim{\'e}nez-Espejo, F.J.; Isaji, Y.; Roveri, M.; Manzi, V.; Kawahata, H.; Ohkouchi, N.
An X-ray spectroscopic perspective on Messinian evaporite from Sicily: Sedimentary fabrics, element distributions, and chemical environments of S and Mg
Geochemistry, Geophysics, Geosystems, 2016
17, 4 - Isaji, Y.; Kawahata, H.; Ohkouchi, N.; Murayama, M.; Tamaki, K.
Terrestrial environmental changes around the Gulf of Aden over the last 210 kyr deduced from the sediment n-alkane record: Implications for the dispersal of Homo sapiens
Geophysical Research Letters, 2015
42, 6 - Isaji, Y.; Kawahata, H.; Ohkouchi, N.; Ogawa, N.O.; Murayama, M.; Inoue, K.; Tamaki, K.
Varying responses to Indian monsoons during the past 220 kyr recorded in deep-sea sediments in inner and outer regions of the Gulf of Aden
Journal of Geophysical Research: Oceans, 2015
120, 11
Presentations
- Y. Isaji; M. K. Nobu; S. Sakai; K. Asahina; H. Imachi; S. Furota; Y. Tsukatani; S. Shimamura; S. Tsujimura; N. O. Ogawa; Y. Takano; N. Ohkouchi
Discovery of a novel heme cofactor in methanogen
Gordon Research Conference Geobiology 2026, 13 Jan. 2026, [Invited] - 伊左治雄太; 延優; 酒井早苗; 朝比奈健太; 井町寛之; 塚谷祐介; 風呂田郷史; 島村繁; 辻村清也; 小川奈々子; 高野淑識; 大河内直彦
新規ヘム補因子の発見
第42回有機地球化学シンポジウム, 04 Nov. 2025 - 伊左治雄太; 杉江恒二; 石川尚人; 小川奈々子; 松本和彦; 吉川知里; 小畑元; 本多牧生; 大河内直彦
東部インド洋のヘム分布に基づく鉄の生物地球化学的解析
2024年度日本地球化学会年会, Sep. 2024 - Y. Isaji; T. Yoshimura; D. Araoka; M. Kurisu; N. Ohkouchi
Heme B as a tool to constrain stable iron isotopic composition of biological iron
JpGU 2024, May 2024
