2021 Fiscal Year Final Research Report

A novel tool for the trophic level of bioessential metals by non-traditioanal stable isotopes

Research Project

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Project/Area Number	19K21908
Research Category	Grant-in-Aid for Challenging Research (Exploratory)
Allocation Type	Multi-year Fund
Review Section	Medium-sized Section 17:Earth and planetary science and related fields
Research Institution	Japan Agency for Marine-Earth Science and Technology
Principal Investigator	Yoshimura Toshihiro 国立研究開発法人海洋研究開発機構, 海洋機能利用部門(生物地球化学プログラム), 研究員 (90710070)
Co-Investigator(Kenkyū-buntansha)	日下宗一郎東海大学, 海洋学部, 特任講師 (70721330) 石川尚人国立研究開発法人海洋研究開発機構, 海洋機能利用部門(生物地球化学プログラム), 副主任研究員 (80609389)
Project Period (FY)	2019-06-28 – 2022-03-31
Keywords	マグネシウム / 安定同位体 / 栄養段階 / 必須ミネラル
Outline of Final Research Achievements	Of the major bioessential metals in marine organism samples, this study focuses on magnesium, which has stable isotopes, to clarify changes in stable isotope ratios in different organs of individual specimen and through the food chain, and to eat habits. It was evaluated as an analysis tool. The bulk and organ-separated analysis of natural marine organism samples and differences in magnesium isotope ratios between tuna samples and feeds cultivated from juveniles and microbial culture samples and media were examined. Each fish organ shows a unique value, and all have lower values than seawater. Tuna muscle has a difference of about -0.4‰ between the compound feed, methane bacteria, and the medium. Therefore it is possible that Mg isotope offsets between redator-prey relationships can be widely applied to marine ecosystems as a change associated with the food chain.
Free Research Field	地球科学
Academic Significance and Societal Importance of the Research Achievements	同位体比を用いた精密食物網解析は，有機物に特化した食物網の解析ツールとして産地の同定や，自然界の捕食・被食関係を知るための化学ツールとして発展してきた。他方で，生体内の元素の元素の挙動は各論的に扱う必要があるが，金属元素の細胞レベルの動態解析には必ずしも自然界の解析に有用な手法が存在していない。また，マグネシウムなどの二族元素は骨や歯などの生体硬組織に多く存在するため，時間を遡った考古資料の解析にも応用できる。同位体比が元素移動の指標になればマイクログラム以下のMg量で利用可能な，元素解析の新規ツールとして期待できる。