10:00 AM - 10:15 AM
[BCG03-04] Ongoing archaeal methanogenesis in an organic- and iodine-rich deep aquifer: molecular evidence from coenzyme factor 430 and methane-specific radiocarbon measurements
Keywords:deep aquifer, radiocarbon measurement, Iodine, methane, small sub-unit rRNA gene sequencing, methanogenic archaea
The results of lipid-based analysis suggested that the biomass of domain archaea was less than 10% of the total prokaryote in deep aquifer, which was supported by the result of the SSU rRNA gene sequencing. The high concentration of native F430 (1.67×107 femto mol/L; Urai et al., 2021) with the absence of the F430 epimers was confirmed in the brine-rich water, suggesting activated ongoing methanogenesis in the deep aquifer. Radiocarbon measurements of methane and dissolved inorganic carbon (DIC) revealed 14C-depleted (Δ14Cmethane and Δ14CDIC, <−997.4‰; Urai et al., 2021), indicating the independent deep habitat and active state of archaeal methanogenesis.
This study was supported in part by the Japan Society for the Promotion of Science (JSPS) with the joint research between the Kanto Natural Gas Development Co., Ltd. and JAMSTEC.
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