Circular protein production via microalgae cultured with digestate derived from methane fermentation

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06350
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 41050:Environmental agriculture-related
• Research Institution: Osaka Metropolitan University (2022); Osaka Prefecture University (2020-2021)
• Principal Investigator: Endo Ryosuke 大阪公立大学, 大学院農学研究科, 講師 (10409146)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: バイオマス利用 / 資源循環 / 食料生産 / 環境調節 / 微生物利用 / サステナビリティ

Outline of Final Research Achievements

In this study, in order to investigate an efficient protein production method from organic wastes, we cultured microalgae Spirulina using a resource recovery culture modified from methane fermentation digestate derived from food residues. The nitrogen form with the highest cultivation rate was nitrate nitrogen, indicating that it is important to convert nitrogen in food residues to nitrate nitrogen by methane fermentation and biological oxidation. Sodium bicarbonate culture medium is suitable as a carbon supply method, and the conversion of carbon dioxide generated by the decomposition of food residues into sodium bicarbonate is considered to be a useful method for utilization. Compared to the chemical fertilizer culture medium, the Spirulina culture using the resource recovery culture medium showed a lower growth rate but a higher percentage of protein.

Free Research Field

農業環境工学

Academic Significance and Societal Importance of the Research Achievements

本研究により、食品残渣からの資源循環型タンパク質生産における，微生物処理がその後の微細藻類の培養速度やタンパク質生産量に様々な影響を及ぼすことが明らかとなった。これは，食品残渣からの効率的な資源回収方法を確立する上で重要な学術的知見であり，同時に，化学肥料や化石燃料への依存度を抑えた持続的食料生産システムの実現に向けた貢献という社会的意義を有する。