Production of essential fatty acids by protozoa and development of the tool for protozoan food web analysis

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04666
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22060:Environmental systems for civil engineering-related
• Research Institution: Kyushu University
• Principal Investigator: Fujibayashi Megumu 九州大学, 工学研究院, 助教 (70552397)
• Co-Investigator(Kenkyū-buntansha): 宮田 直幸 秋田県立大学, 生物資源科学部, 教授 (20285191)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 食物連鎖 / 脂肪酸動態 / 湖沼 / 高度不飽和脂肪酸

Outline of Final Research Achievements

Highly unsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid are important nutrients for animal growth, reproduction, and survival. These fatty acids are synthesized by algal species and transferred to higher trophic level through food chain. Here, we aimed to demonstrate that protozoa also have the role of HUFA synthesis and supply to aquatic food webs. In addition, the new methods for evaluation of dietary contribution of protozoa in aquatic ecosystems was developed. We found one ciliate species could synthesize essential fatty acids and EPA. Moreover, we demonstrated that stable carbon isotope ratios of essential fatty acids can be a tracer of ciliate in an aquatic food web.

Free Research Field

水環境生態工学

Academic Significance and Societal Importance of the Research Achievements

これまで藻類が担っていると考えられてきた水圏生態系における高度不飽和脂肪酸供給の役割を原生動物も担っている可能性を示した。さらに、申告な湖沼環境問題を引き起こす藍藻を餌とした場合でも、高度不飽和脂肪酸を合成できることが示された。このことは、湖沼の水質改善や生物多様性に対する原生動物の役割が大きいことを示しており、今後は原生動物の機能を活用した生態工学的な湖沼環境改善技術の開発が期待される。