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Rock-crushing derived hydrogen directly supports a methanogenic community: significance for the deep biosphere.

ABSTRACT: Microbial populations exist to great depths on Earth, but with apparently insufficient energy supply. Earthquake rock fracturing produces H2 from mechanochemical water splitting, however, microbial utilization of this widespread potential energy source has not been directly demonstrated. Here, we show experimentally that mechanochemically generated H2 from granite can be directly, long-term, utilized by a CH4 producing microbial community. This is consistent with CH4 formation in subsurface rock fracturing in the environment. Our results not only support water splitting H2 generation as a potential deep biosphere energy source, but as an oxidant must also be produced, they suggest that there is also a respiratory oxidant supply in the subsurface which is independent of photosynthesis. This may explain the widespread distribution of facultative aerobes in subsurface environments. A range of common rocks were shown to produce mechanochemical H2 , and hence, this process should be widespread in the subsurface, with the potential for considerable mineral fuelled CH4 production.

SUBMITTER: Parkes RJ

PROVIDER: S-EPMC7379504 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature

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Rock-crushing derived hydrogen directly supports a methanogenic community: significance for the deep biosphere.

Parkes Ronald John RJ Berlendis Sabrina S Roussel Erwan G EG Bahruji Hasiliza H Webster Gordon G Oldroyd Anthony A Weightman Andrew J AJ Bowker Michael M Davies Philip R PR Sass Henrik H

Environmental microbiology reports 20181226 2

Microbial populations exist to great depths on Earth, but with apparently insufficient energy supply. Earthquake rock fracturing produces H2 from mechanochemical water splitting, however, microbial utilization of this widespread potential energy source has not been directly demonstrated. Here, we show experimentally that mechanochemically generated H2 from granite can be directly, long-term, utilized by a CH4 producing microbial community. This is consistent with ...[more]

PMID: 30507067

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Rock-crushing derived hydrogen directly supports a methanogenic community: significance for the deep biosphere.

Publications

Rock-crushing derived hydrogen directly supports a methanogenic community: significance for the deep biosphere.

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