Study on the production of monohalomethanes by Labyrinthula and assessment of their environmental impact

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K12358
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 63040:Environmental impact assessment-related
• Research Institution: Nihon University
• Principal Investigator: HASHIMOTO Sinya 日本大学, 文理学部, 教授 (10228413)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: ラビリンチュラ / 揮発性有機化合物 / モノハロメタン

Outline of Final Research Achievements

The results of this study indicate that Labyrinthula species produce the monohalomethanes such as CH3Cl, CH3Br, and CH3I. The amounts produced varied among species, with some species being able to explain 6-23% of the marine CH3Cl concentration and 0.5-0.6% of the CH3I concentration, indicating that they may be one of the major sources of CH3Cl in the ocean. The results of incubation at 20°C, 25°C, and 30°C, respectively, showed that the production of monohalomethanes was affected by incubation temperature; for example, the production of CH3I decreased and that of CH3Cl increased as the seawater temperature increased. It was also suggested that trace metals may have an effect on the formation of monohalomethanes.

Free Research Field

生態環境化学

Academic Significance and Societal Importance of the Research Achievements

大気中のモノハロメタンは成層圏オゾン分解の触媒作用を示す。現在、モノハロメタンの地球規模の収支モデルにおいて、既知の生成源は地球規模の生成量を説明するには不十分である。本研究の成果より、ラビリンチュラ類は海洋でのモノハロメタンの生成源としての役割を担っていること、また地球環境の温度変化がモノハロメタンの生成に影響を与えうることが明らかとなった。