Biogas production using anaerobic groundwater containing a subterranean microbial community associated with the accretionary prism

Abstract

Summary In a deep aquifer associated with an accretionary prism, significant methane ( CH 4 ) is produced by a subterranean microbial community. Here, we developed bioreactors for producing CH 4 and hydrogen ( H 2 ) using anaerobic groundwater collected from the deep aquifer. To generate CH 4 , the anaerobic groundwater amended with organic substrates was incubated in the bioreactor. At first, H 2 was detected and accumulated in the gas phase of the bioreactor. After the H 2 decreased, rapid CH 4 production was observed. Phylogenetic analysis targeting 16 S rRNA genes revealed that the H 2 ‐producing fermentative bacterium and hydrogenotrophic methanogen were predominant in the reactor. The results suggested that syntrophic biodegradation of organic substrates by the H 2 ‐producing fermentative bacterium and the hydrogenotrophic methanogen contributed to the CH 4 production. For H 2 production, the anaerobic groundwater, amended with organic substrates and an inhibitor of methanogens (2‐bromoethanesulfonate), was incubated in a bioreactor. After incubation for 24 h, H 2 was detected from the gas phase of the bioreactor and accumulated. Bacterial 16 S rRNA gene analysis suggested the dominance of the H 2 ‐producing fermentative bacterium in the reactor. Our study demonstrated a simple and rapid CH 4 and H 2 production utilizing anaerobic groundwater containing an active subterranean microbial community.

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Identifiers

DOI

10.1111/1751-7915.12179

Journal

Microbial Biotechnology

Year

2015