Cultivation of photosynthetic ammonia-oxidizing microorganisms using near infrared light and development of an innovative wastewater treatment process

• Project/Area Number: 18K18884
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 22:Civil engineering and related fields
• Research Institution: Hiroshima University
• Principal Investigator: Kindaichi Tomonori 広島大学, 先進理工系科学研究科(工), 准教授 (10379901)
• Project Period (FY): 2018-06-29 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000); Fiscal Year 2020: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2018: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
• Keywords: アナモックス / 光合成 / 窒素除去

Outline of Final Research Achievements

The purpose of this study is to develop an innovative wastewater treatment process by culturing microorganisms responsible for anaerobic photosynthetic ammonia oxidation. During the cultivation, near-infrared light that cuts visible light was irradiated to the reactor to prevent the growth of common photosynthetic microorganisms.
As a result of irradiation of near infrared light, cyanobacteria possessed chlorophyll accounted for 40-50% of the total bacteria in a partially greened biomass, although ammonia was slightly removed from the reactor, suggesting the cultivation of microorganisms responsible for anaerobic photosynthetic ammonia oxidation.

Academic Significance and Societal Importance of the Research Achievements

水(酸素発生型)や硫化水素(非酸素発生型)と光エネルギーを用いてCO2を同化する光合成微生物はよく知られている。一方、本研究で対象とするアンモニアと光エネルギーを用いてCO2を同化する光合成微生物はこれまでに発見されておらず、その微生物の発見・培養 自体が極めて探索的性質の強い研究である。アンモニア光合成微生物の培養ができれば、植物工場で使用されている近赤外線LED による光照射を組み合わせることで、大量の酸素消費と低効率が問題となっていた排水処理の硝化プロセスを大きく転換させる革新的水処理プロセスとなり得る。