Removal and recovery of phosphorus from nutrient-rich environmental water using polyphosphate-accumulating microalgae with ammonium tolerance

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K15892
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 40030:Aquatic bioproduction science-related
• Research Institution: The University of Tokyo
• Principal Investigator: Katayama Tomoyo 東京大学, 大学院農学生命科学研究科(農学部), 特任助教 (10755656)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 微細藻類 / リン回収 / ポリリン酸 / アンモニア / 環境負荷低減 / 廃水

Outline of Final Research Achievements

This study aimed to remove phosphate and ammonia from the nutrient-rich environmental water and recover phosphorus using microalgae. Among 151 strains isolated from Malaysia and Japan, 11 strains were selected for their ammonia tolerance and high growth potential. The highest accumulation of PolyP was observed in strain SLG4-06, which was determined to be a promising strain for phosphorus removal and recovery. The effects of light intensity and temperature on PolyP accumulation capacity were examined for this strain. The results showed that the growth rate and the amount of PolyP were maximum at 25℃ and 250 μE/m2/s, indicating that the SLG4-06 tended to accumulate phosphorus as PolyP in the cells during the exponential phase.

Free Research Field

海洋生物学

Academic Significance and Societal Importance of the Research Achievements

PolyP蓄積微細藻類の探索を行った研究例は希少な中，本研究では珪藻やハプト藻に比べ，緑藻はPolyPを蓄積しやすいことを明らかにした。本研究で選定されたSLG4-06株は，未記載種（緑藻クロレラ目の新属）であることがわかり，PolyP蓄積藻類として初めての報告である。今後は，細胞内へのリン酸塩の取り込みをより短期間で行う培養技術を開発し，リン除去率及びPolyP蓄積率のさらなる向上に挑戦し，水質環境汚染およびリン資源問題の解決に寄与する研究を展開していきたい。