Characterization of microbial assemblages associated with large-scale thawing of permafrost

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K20462
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 63040:Environmental impact assessment-related
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Nakai Ryosuke 国立研究開発法人産業技術総合研究所, 生命工学領域, 研究員 (90637802)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 微生物 / 細菌 / バクテリア / 永久凍土 / 環境影響評価

Outline of Final Research Achievements

This study investigated unseen/uncultured microorganisms present in the ice complex of the Alaskan permafrost. Microbiome analysis revealed that bacterial members belonging to Actinobacteria, Proteobacteria, Chlamydiae, Planctomycetes, and Firmicutes, as well as archaeal members affiliated with Euryarchaeota and Thaumarchaeota were dominant in the studied samples. Some samples also contained novel lineages belonging to uncultivated candidate divisions, Acidobacteria, and Gemmatimonadetes. Metagenomic analysis also detected uncultivated members with metabolic potentials related to organic matter degradation and gas production, and the relationship between the metabolic characteristics obtained and the geochemical data is currently being analyzed. In addition, culturing efforts have led to the isolation of phylogenetically novel proteobacterial strains.

Free Research Field

微生物生態学

Academic Significance and Societal Importance of the Research Achievements

地球環境変動によって大融解が促される永久凍土は、有機炭素の巨大な貯蔵庫である。この種の凍土には、肉眼では見えないが、多種多様な微生物（特にバクテリアやアーキアなど原核生物）を含んでいる。凍土融解による物質循環インパクトを考察するうえでは、それら微生物の実態と代謝機能の情報も重要であると考える。本研究で得た微生物群集構造とその生理生態の知見は、凍土融解時に現場で増殖して機能しうる微生物を考究するための基盤的知見になる。