Endolithic Microbial Habitats Hosted in Carbonate Nodules Currently Forming within Sediment at a High Methane Flux Site in the Sea of Japan

• Yanagawa, Katsunori

• Shiraishi, Fumito

• Tanigawa, Yusuke

• Maeda, Toshinari

• Mustapha, Nurul Asyifah

• Owari, Satoko

• Tomaru, Hitoshi

• Matsumoto, Ryo

• Kano, Akihiro

Bibliographic Information

Other Title

• Endolithic microbial habitats hosted in carbonate nodules currently forming within sediment at a high methane flux site in the sea of Japan

Abstract

Concretionary carbonates in deep-sea methane seep fields are formed as a result of microbial methane degradation, called anaerobic oxidation of methane (AOM). Recently, active microorganisms, including anaerobic methanotrophic archaea, were discovered from methane seep-associated carbonate outcroppings on the seafloor. However sedimentary buried carbonate nodules are a hitherto unknown microbial habitat. In this study, we investigated the microbial community structures in two carbonate nodules collected from a high methane flux site in a gas hydrate field off the Oki islands in the Sea of Japan. The nodules were formed around sulfate-methane interfaces (SMI) corresponding to 0.7 and 2.2 m below the seafloor. Based on a geochemical analysis, light carbon isotopic values ranging from −54.91‰ to −37.32‰ were found from the nodules collected at the shallow SMI depth, which were attributed to the high contributions of AOM-induced carbonate precipitation. Signatures of methanotrophic archaeal populations within the sedimentary buried nodule were detected based on microbial community composition analyses and quantitative real-time PCR targeted 16S rRNA, and functional genes for AOM. These results suggest that the buried carbonate nodule currently develops AOM-related microbial communities, and grows depending on the continued AOM under high methane flux conditions.

Journal Article

Journal

• Geosciences

  Geosciences 9 (11), 463-1-463-16, 2019-10-30

  MDPI

Keywords

• carbonate nodule
• endolithic microbial community
• methane

Details

• CRID: 1050282814043530112
• NII Article ID: 120006767886
• ISSN: 20763263
• DOI: 10.3390/geosciences9110463
• HANDLE: 10228/00007444
• Web Site: https://kyutech.repo.nii.ac.jp/records/6234
• Web Site: https://www.mdpi.com/2076-3263/9/11/463/pdf
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • Crossref
  • CiNii Articles
  • KAKEN