Deputy Director of Japan Agency for Marine-Earth Science and Technology, Atsushi Takano, and Research Student of Atsushi Urai of Shinshu University, in collaboration with Kanto Natural Gas Development Co., Ltd. and the University of Tokyo, analyzed samples collected from the South Kanto Gas Field and lived in deep fluids. It was revealed that Archaea (archaea) continue to produce methane.It was also found that a diverse microbial community exists in the deep fluid.

 In the deep underground of the Kanto region, a stratum made of seafloor sediments from about 300 to 40 years ago is distributed, and the groundwater in the stratum contains water-soluble natural gas and high-concentration iodine.The natural gas produced is said to be the decomposition of organic matter buried in the ground by microorganisms, and in fact, the gene for methanogenic archaea has been detected in the groundwater around Mobara City, Chiba Prefecture.However, it was difficult to accurately evaluate the abundance and activity of methanogenic archaea living deep underground.

 In the research, self-spraying gas and groundwater samples were collected from the deep underground aquifer at two survey points around Mobara City, Chiba Prefecture.As a result of extracting and measuring the coenzyme F2 from this sample, a high concentration of F430 was observed. F430 is an unstable compound that rapidly isomerizes (epimerizes) or degrades when released extracellularly from methanogenic archaea.However, no epimer of F430 was detected in this sample, and it was considered that the methanogenic archaea in the deep subterranean aquifer had high methanogenic activity.

 Furthermore, by performing ribosomal RNA gene analysis, the existence of a wide variety of microorganisms in the deep subterranean aquifer in addition to methanogenic archaea was confirmed.In addition, the deep underground aquifer had almost no carbon supply from the surface layer due to rainwater or seawater, forming an independent underground biosphere.

 This discovery is expected to elucidate the ecology of prokaryotes in the subterranean area and the methanogenic process in deep subterranean aquifers.

Paper information:[ACS Earth and Space Chemistry] Origin of Deep Methane Associated with a Unique Community of Microorganisms in an Organic- and Iodine-Rich Aquifer

Tokyo University

Established in the 10th year of the Meiji era.A university with the longest history in Japan and at the forefront of Japanese knowledge

The University of Tokyo was established in 1877 (Meiji 10) by integrating the Tokyo Kaisei School and the Tokyo Medical School.Since its establishment, it has developed education and research in a unique way in the world as a leading university in Japan and an academic center for the fusion of East and West cultures.As a result, many human resources have been produced in a wide range of fields, and many research achievements […]

Shinshu University

Fostering human resources with abundant human and practical skills in local and global societies

Shinshu University is a wide-area campus-type general university with five campuses in Nagano Prefecture.It consists of eight faculties: humanities, pedagogy, economics, science, medicine, engineering, agriculture, and textiles, and conducts education and research to acquire a wide range of education and basic abilities.Utilizing common education across faculties and the regional characteristics of Shinshu, which is rich in nature […]

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