Geological degassing enhances microbial metabolism in the continental subsurface

Bornemann, T. L.; Adam, P. S.; Turzynski, V.; Schreiber, U.; Figueroa-Gonzalez, P. A.; Rahlff, J.; Koester, D.; Schmidt, T. C.; Schunk, R.; Krauthausen, B.; Probst, A. J.

doi:10.1101/2020.03.07.980714

bioRxiv · 10.1101/2020.03.07.980714

Geological degassing enhances microbial metabolism in the continental subsurface

Bornemann, T. L.·Adam, P. S.·Turzynski, V.·Schreiber, U.·Figueroa-Gonzalez, P. A.·Rahlff, J.·Koester, D.·Schmidt, T. C.·Schunk, R.·Krauthausen, B.·Probst, A. J.

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Abstract

Mantle degassing provides a substantial amount of reduced and oxidized gases shaping microbial metabolism at volcanic sites across the globe, yet little is known about its impact on microbial life under non-thermal conditions. Here, we characterized deep subsurface fluids from a cold-water geyser driven by mantle degassing using genome-resolved metagenomics to investigate how the gases impact the metabolism and activity of indigenous microbes compared to non-impacted sites. While species-specific analyses of Altiarchaeota suggest site-specific adaptations and a particular biogeographic pattern, chemolithoautotrophic core features of the communities appeared to be conserved across 17 groundwater ecosystems between 5 and 3200 m depth. We identified a significant negative correlation between ecosystem depth and bacterial replication, except for samples impacted by high amounts of subsurface gases, which exhibited near-surface activity. Our results suggest that geological degassing leads to higher nutrient flows and microbial activity in the deep subsurface than previously estimated.

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Bornemann, T. L., Adam, P. S., Turzynski, V., Schreiber, U., Figueroa-Gonzalez, P. A., Rahlff, J., Koester, D., Schmidt, T. C., Schunk, R., Krauthausen, B., Probst, A. J.. 2020-03-08. Geological degassing enhances microbial metabolism in the continental subsurface. https://doi.org/10.1101/2020.03.07.980714

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