Exploration and isolation of nosZ clade II type N2O-reducing bacteria by a novel enrichment device

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K12616
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Environmental engineering and reduction of environmental burden
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Terada Akihiko 東京農工大学, 工学(系)研究科(研究院), 准教授 (30434327)
• Co-Investigator(Renkei-kenkyūsha): HORI Tomoyuki 国立研究開発法人産業技術総合研究所, 環境管理研究部門, 主任研究員 (20509533)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 亜酸化窒素（N2O） / N2O還元細菌 / nosZ clade IIタイプ / 集積培養装置 / アンプリコンシーケンス / 呼吸活性 / 動力学的解析

Outline of Final Research Achievements

To mitigate emission of N2O, known as a highly-potent greenhouse and ozone-depleting gas, this study aimed at enriching and isolating nosZ clade II type N2O-reducing bacteria as promising N2O consumers with high efficiency. By developing a novel enrichment technology, Azospira sp., affiliated with nosZ clade II type, was successfully isolated. One of the strains in the bacterium, Azospira sp. strain I09, showed N2O-reducing activity in the presence of oxygen. Immobilization of Azospira sp. strain I13 into alginate gel allowed consumption of N2O even under microaerophilic conditions. To explore non-denitrifying N2O-reducing bacteria, an anammox reactor was subjected to the microbial community analysis. The analysis underpinned that the phylum Chloroflexi, detected with a relatively high abundance following anammox bacteria, was a potential candidate as non-denitrifying N2O-reducing bacteria.

Free Research Field

環境バイオテクノロジー