Exploring non-denitrifying N2O-reducing bacteria in wastewater treatment systems

2019 Fiscal Year Final Research Report

• Project/Area Number: 19K21555
• Project/Area Number (Other): 18H06492 (2018)
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund (2019); Single-year Grants (2018)
• Review Section: 1101:Environmental analyses and evaluation, environmental conservation measure and related fields
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Suneaga Toshikazu 東京農工大学, 工学(系)研究科(研究院), 特任助教 (80828377)
• Project Period (FY): 2018-08-24 – 2020-03-31
• Keywords: 亜酸化窒素 / 脱窒 / ゲノム解析 / 排水処理 / 地球温暖化 / 温室効果ガス

Outline of Final Research Achievements

An urgent issue is a reduction of nitrous oxide (N2O) emission, a powerful global warming and ozone-depleting substance. This study focused on N2O-reducing bacteria, reducing N2O to dinitrogen, especially non-denitrifying N2O-reducing bacteria that cannot reduce nitrite and nitrate. The aim in this study was to explore and detecting their activity in wastewater treatment systems.
15N tracer method was developed to determine the true rate of production and consumption of N2O. The activity of N2O-reducing bacteria, presumed to coexist with Anammox, was detected. In addition, the N2O-reducing bacteria in anammox biomass were explored through metagenomic analysis and enrichment reactor operation.

Free Research Field

化学工学, 環境微生物学, 窒素循環, 環境工学

Academic Significance and Societal Importance of the Research Achievements

低環境負荷型の社会形成を目指し、人的要因に由来するN2O放出の削減が求められている。N2O還元細菌は有効なN2O削減技術への応用が期待されているが、その全容や活性は未解明な点が多い。本研究では特に、N2Oのみを消費できる非脱窒性N2O還元細菌の解明にむけて、その活性の検出や探索を試みた。これらの試みは世界的にも初めてであり、今後これらの手法を用いてこの細菌群の有用性が明らかになれば、環境負荷低減に向けた一歩となると考えられる。