Bioelectrochemical Stimulation of Electromethanogenesis at a Seawater-Based Subsurface Aquifer in a Natural Gas Field

Abstract

Ishii et al. Bioelectrochemical Stimulation of Subsurface Electro-Microbiome family Desulfuromonadaceae dominating in the early stage of the operation. The family Geobacteraceae (mainly genus Geoalkalibacter) became dominant during the longerterm operation, suggesting that these families were correlated with electrode-respiring reactions. These results indicate that the BES reactors with voltage application effectively activated a subsurface DIET-related methanogenic microbiome in the natural gas field, and specific electrogenic bacteria and electromethanogenic archaea were identified within the anode and/or cathode biofilms.

Origin of Deep Methane Associated with a Unique Community of Microorganisms in an Organic- and Iodine-Rich Aquifer

“…The reservoir rocks of this gas field consist of turbidites (alternating beds of sandstone and mudstone) in the Umegase to Katsuura formations of the Kazusa Group. The depths and ages of the formations are about 100–3000 m and about 0.8–2.4 Ma, respectively. , The gas field does not contain oil because of the low geothermal heat flow and short duration (and rapidity) of sedimentation. , Previous studies reported that methane in the Southern Kanto gas field has a typical biogenic origin and was formed by a type of hydrogenotrophic methanogenesis, as indicated by its gas composition and methane isotopic ratios (C 1 /C 2 = 6.1 × 10 3 , δ 13 C methane , −67‰ vs Vienna Pee Dee Belemnite [VPDB] and δD methane , −185‰ vs standard mean ocean water). , On the basis of archaeal 16S rRNA gene analysis and culturing of brine-rich water from the deep subsurface environment at Mobara, it has been suggested that there are methanogenic communities presently living in the deep aquifer. ,, However, there are some organic geochemical aspects of the microbial ecology in the organic and iodine-enriched deep biosphere that are still unknown.…”

“…PCR amplification of the SSU rRNA gene was performed using TaKaRa LA Taq (TaKaRa Bio Inc., Japan) with a universal primer pair (530F/907R), which contained overhang adapters at the 5′ ends. The detailed procedures for library construction, sequencing by MiSeq (Illumina, USA), and data analysis were described previously . The SSU rRNA gene tag sequencing data from this study have been deposited in a short read archive with the accession numbers SRS5817427–5817429 and SRX7574760.…”

“…34,35 On the basis of archaeal 16S rRNA gene analysis and culturing of brine-rich water from the deep subsurface environment at Mobara, it has been suggested that there are methanogenic communities presently living in the deep aquifer. 15,36,37 However, there are some organic geochemical aspects of the microbial ecology in the organic and iodine-enriched deep biosphere that are still unknown.…”

“…The detailed procedures for library construction, sequencing by MiSeq (Illumina, USA), and data analysis were described previously. 37 The SSU rRNA gene tag sequencing data from this study have been deposited in a short read archive with the accession numbers SRS5817427−5817429 and SRX7574760.…”

Fundamentals, Applications, and Future Directions of Bioelectrocatalysis

“…Some useful attempts have been carried out to synchronously realize the CH 4 production and the treatment of domestic wastewater, 894 dairy farm wastewater, 895 and a seawater-based subsurface aquifer in a natural gas field. 896 For the mediated electron transfer (MET)-based electromethanogenesis depending on H 2 production, Marshall and co-workers first reported the reduction of CO 2 to a mixture of methane, acetate, hydrogen, and formate, using enriched mixed cocultures consisting of >93% Methanobacterium and ∼5% Methanobrevibacte originated from brewery wastewater under the potential of −0.59 V vs SHE. 897 In subsequent research, a novel electrode design consisted of porous nickel hollow fibers, which acted as an inorganic electrocatalyst for hydrogen generation from proton reduction and as a gas transfer membrane for direct CO 2 delivery to CO 2 -fixing hydrogenotrophic methanogens on the cathode through the pores of the hollow fibers.…”