Anaerobic methane-oxidizing activity in a deep underground borehole dominantly colonized by Methanoperedenaceae

Nishimura, Hiroki*; Kozuka, Mariko*; Fukuda, Akari*; Ishimura, Toyoho*; Amano, Yuki; Beppu, Hikari*; Miyakawa, Kazuya; Suzuki, Yohei*

Environmental Microbiology Reports (Internet), 15(3), p.197 - 205, 2023/06

https://doi.org/10.1111/1758-2229.13146

The family Methanoperedenaceae archaea mediate anaerobic oxidation of methane (AOM). We newly developed a high-pressure laboratory incubation system and investigated groundwater from 214- and 249-m deep boreholes at Horonobe Underground Research Laboratory, Japan, where the high and low abundances of Methanoperedenaceae archaea have been revealed, respectively. We incubated the samples amended with or without amorphous Fe(III) and C-labelled methane at an in-situ pressure of 1.6 MPa. After three to seven-day incubation, AOM activities were not detected from the 249-m sample but from the 214-m sample. The AOM rates were 93.740.6 and 27.737.5 nM/day with and without Fe(III) amendment. Suspended particulates were not visible in the 249-m sample on the filter, while they were abundant and contained amorphous Fe(III) and Fe(III)-bearing phyllosilicates in the 214-m sample. This supports the in-situ activity of Fe(III)-dependent AOM in the deep subsurface borehole.

The FeSe(cr) solubility determined by solubility experiments of Se co-existing with Fe

Doi, Reisuke; Uchikoshi, Keiji*; Beppu, Hikari*

Journal of Nuclear Science and Technology, 53(10), p.1554 - 1562, 2016/10

https://doi.org/10.1080/00223131.2015.1137245

To determine log K for FeSe(cr) dissolution reaction, solubility experiments of Se co-existing with Fe were performed. Temperature was maintained at 348 K. Se concentration as a function of equilibration periods indicated that Se concentrations were similar at different equilibration periods. Only FeSe(cr) was detected as the Se solid phase by XRD analysis of the equilibrated precipitates. and pH of the equilibrated suspensions ranged from -188.6 to -4.9 mV vs. SHE and 6.00 to 8.76, respectively. Se and Fe are thermodynamically stable in this region. Interpretations using SIT model showed that the relationship between and the measured concentrations could be interpreted well when in the following equation n = 0.500.01 and log K = -17.240.31 : 4FeSe(cr) = 4nFe + Se + (8n - 2)e. The logK value calculated from the available thermodynamic data agrees with that determined here.

Solubility of selenium in the presence of iron under reducing conditions

Doi, Reisuke; Uchikoshi, Keiji*; Beppu, Hikari*

no journal, , 

In order to determine the solubility-controlling solid of Se under reducing conditions, solubility experiments of Se were performed from oversaturation direction in the presence of Fe under reducing conditions. The Se concentration as a function of equilibration periods suggested the attainment of equilibrium in our system within a month. Only FeSe was detected as the Se solid phase by XRD analysis of the solid samples from the equilibrated suspensions. Interpretations using the specific ion interaction theory model showed that the relationship between Eh and the measured concentrations of Se and Fe could be interpreted well by the dissolution reaction of FeSe. Therefore, we conclude that FeSe is most likely the solubility-controlling solid of Se under these conditions.

Investigation of sorption reversibility of Am(III) and the other nuclides on bentonite colloids

Nakata, Kotaro*; Ishidera, Takamitsu; Kurosawa, Seiichi*; Hayashi, Masanori*; Beppu, Hikari*; Sukegawa, Akihiro*

no journal, , 

no abstracts in English

Vast metabolic and phylogenetic diversity shared across deep subsurface environments

Amano, Yuki; Diamond, S.*; Lavy, A.*; Anantharaman, K.*; Miyakawa, Kazuya; Iwatsuki, Teruki; Beppu, Hikari*; Suzuki, Yohei*; Thomas, B. C.*; Banfield, J. F.*

no journal, , 

Existence and the role of subsurface biofilm in the deep sedimentary rock environment of the Horonobe area, Hokkaido, Japan

Amano, Yuki; Beppu, Hikari*; Endo, Takashi*; Nemoto, Kazuaki*; Sato, Tomofumi*; Thomas, B. C.*; Banfield, J. F.*

no journal, , 

The Fe(III)-dependent anaerobic methane-oxidizing activity in a deep underground borehole demonstrated by in-situ pressure groundwater incubation

Nishimura, Hiroki*; Kozuka, Mariko*; Fukuda, Akari*; Ishimura, Toyoho*; Amano, Yuki; Beppu, Hikari*; Miyakawa, Kazuya; Suzuki, Yohei*

no journal, , 

The family Methanoperedenaceae archaea mediate anaerobic oxidation of methane (AOM). We newly developed a high-pressure laboratory incubation system and investigated groundwater from 214- and 249-m deep boreholes at Horonobe Underground Research Laboratory, Japan, where the high and low abundances of Methanoperedenaceae archaea have been revealed, respectively. We incubated the samples amended with or without amorphous Fe(III) and C-labelled methane at an in-situ pressure of 1.6 MPa. After three to seven-day incubation, AOM activities were not detected from the 249-m sample but from the 214-m sample. The AOM rates were 93.740.6 and 27.737.5 nM/day with and without Fe(III) amendment. Suspended particulates were not visible in the 249-m sample on the filter, while they were abundant and contained amorphous Fe(III) and Fe(III)-bearing phyllosilicates in the 214-m sample. This supports the in-situ activity of Fe(III)-dependent AOM in the deep subsurface borehole.

Extensive and active methane-metabolizing microbiomes unveiled in deep sedimentary rocks

Nishimura, Hiroki*; Kozuka, Mariko*; Fukuda, Akari*; Ishimura, Toyoho*; Amano, Yuki; Beppu, Hikari*; Miyakawa, Kazuya; Suzuki, Yohei*

no journal, , 

no abstracts in English