Survival strategy with light~Unique photoheterotrophs in the ocean

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K12206
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 63010:Environmental dynamic analysis-related
• Research Institution: Japan Women's University (2023); The University of Tokyo (2021-2022)
• Principal Investigator: TAKABE Yuki 日本女子大学, 家政学部, 助教 (80635839)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 光従属栄養細菌 / 光合成 / 炭素循環 / カロテノイド

Outline of Final Research Achievements

The present study focused on photoheterotrophic bacteria, whose contribution to the carbon cycle has been unclear within the framework of conventional ecosystem in the ocean, and aimed to clarify their dynamics and eco-physiological characteristics in the environment. Unlike other heterotrophs, photoheterotrophs utilize light energy for their biological activities and have an advantage in cell growth and survival, which may contribute to increasing the efficiency of carbon cycling in ecosystems in the ocean. Through this study, the preset study has clarified the characteristics of the carbon cycle by photoheterotrophic bacteria in the ecosystems, and have worked toward a paradigm shift in the conventional image of the carbon cycle of the ocean.

Free Research Field

海洋微生物生理生態学

Academic Significance and Societal Importance of the Research Achievements

本研究では、光従属栄養細菌として酸素非発生型好気性光合成細菌 (aerobic anoxygenic phototrophic bacteria, 以下AAnPBと称する) という機能細菌群に注目した。AAnPBは全球海洋表層に普遍的に分布し、海洋炭素循環を駆動するキープレイヤーである。AAnPBは光合成によるエネルギー生産により従属栄養的増殖を補完することで、他の従属栄養細菌よりも高効率で炭素循環を駆動出来る潜在性がある。海洋炭素循環像にAAnPBという新たな存在を位置付けることにより、これまでの従属栄養細菌中心で見積もられていた循環効率と循環量がより正確なものになると予想される。