Elucidation of novel CO2 transport mechanism contributed by biogenic polyamines

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K19237
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 40:Forestry and forest products science, applied aquatic science, and related fields
• Research Institution: Kitasato University
• Principal Investigator: Yasumoto Ko 北里大学, 海洋生命科学部, 講師 (00448200)
• Co-Investigator(Kenkyū-buntansha): 安元 加奈未 徳島文理大学, 薬学部, 助教 (70412393) ; 安元 純 琉球大学, 農学部, 助教 (70432870)
• Project Period (FY): 2018-06-29 – 2020-03-31
• Keywords: ポリアミン / 二酸化炭素 / 炭酸カルシウム

Outline of Final Research Achievements

We hypothesized that the biogenic polyamines are related to the alkalization of the calcifying fluids. To ascertain such hypothesis, we investigated the effect of a polyamine transporter inhibitors (PTI) on pH in the calcifying fluids in primary polyps of Acroporid corals. When the primary polyps were treated with PTI, the pH of the calcifying fluids in polyps was significantly lower than that of polyps without the treatment. In addition, we examined the effects of CO2 levels on in vitro aragonite CaCO3 formation by using biogenic polyamines and on in vivo aragonite formation in the skeleton of juvenile Acropora digitifera corals. As a result, we showed that the calcification rate clearly decreased both in vitro and in vivo CaCO3 formation, accompanying the increase of the CO2 level. Our findings elucidated novel physiological functions of polyamines, thus providing a new concept on the calcification mechanisms in marine organisms.

Free Research Field

生物有機化学，バイオミネラリゼーション

Academic Significance and Societal Importance of the Research Achievements

本研究成果は、これまで未解明な点が多かった海洋生物の石灰化反応に関与する二酸化炭素輸送や細胞内のpH調整に関する新たな生理機能を提唱し，学術的に新しい視点を与えると期待できる。また，海洋生物の石灰化反応が二酸化炭素固定反応であること，海水を利用した新たな二酸化炭素削減法の創出といった社会を大きく変革・転換させ、飛躍的な発展に貢献する社会的意義も有する成果である。