Unveiling the complex nitrogen cycle by using novel stable isotope labeling incubations.

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K21341
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 1101:Environmental analyses and evaluation, environmental conservation measure and related fields
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: Kobayashi Kanae 国立研究開発法人海洋研究開発機構, 超先鋭研究開発部門(超先鋭研究開発プログラム), Young Research Fellow (20908264)
• Project Period (FY): 2021-08-30 – 2024-03-31
• Keywords: 硝化 / 脱窒 / 嫌気的アンモニウム酸化 / 安定同位体比 / 窒素循環 / 深海堆積物

Outline of Final Research Achievements

In this study, we challenged to investigate N-related microbial community composition and their nitrogen flux in the deep-sea sediments by conducting both of biogeochemical (concentration and isotope composition of nitrogen compounds) and molecular analyses (SSU rRNA gene tag sequencing). Sediment columns were collected from sites with different depth and surface productivities including Sagami Bay, abyssal plain and Izu-Ogasawara Trench. Our results provide insight into the pattens of distribution of nitrogen-related microorganisms and N fluxes of each sampling sites.

Free Research Field

微生物生態学

Academic Significance and Societal Importance of the Research Achievements

深海堆積物中の微生物系が駆動する無機窒素循環の評価を通じて、グローバルな深海底における窒素除去評価の基盤的データを得ることができた。また、本研究では新たな取り組みとして地球化学分析（各種窒素化合物の濃度および安定同位体組成）と、微生物の分子生態解析（群集構造および窒素代謝機能遺伝子）を組み合わせて、これまで未解明であった深海堆積物中の窒素代謝微生物の鉛直分布と物質フラックスの両方を求めて深海底における物質循環を議論する足がかりとなると考えられる。