The Deep Subsurface Biosphere and its Substrates Along a One-Million-Year Ferruginous Lake Archive DOI Creative Commons
Fátima Ruiz-Blas, André Friese, Alexander Bartholomäus

et al.

Microbial Ecology, Journal Year: 2025, Volume and Issue: 88(1)

Published: June 3, 2025

Lake Towuti, Indonesia, is an ancient stratified lake with ferruginous (iron-rich, sulfate-poor) anoxic bottom water conditions and a long depositional record affected by redox changes in the column sediments. As modern analogue of Earth's early oceans, it enables study active microbial subsurface biosphere its role organic matter iron mineralization. Combining 16S rRNA genes, cell counts, pore geochemistry, bulk sediment profiles from 100-m-long core, we present first comprehensive characterization deep along one-million-year lacustrine archive. Electron acceptors became depleted at shallow depths, resulting drastic decrease densities fermentative zone, where Bathyarchaeia dominate community composition. Although alpha beta diversity reflected initial depletion substrates during burial, they also varied across successive lithologies, indicating that composition subsequent to deposition affects diversity. The upper sediments (0-20 mblf) sheltered dense diverse involved remineralization, actively producing converting volatile fatty acids into carbon dioxide methane. Deeper (20-70 contained low-diversity communities adapted nutrient scarcity. In contrast, deepest (70-100 increased reflecting greater availability terrestrial origin. Despite being prime constituents biosphere, gene was observed discrete layers (tephra, diatom ooze, peat). This demonstrated remained traceable, while drove reductive diagenesis.

Language: Английский

The Deep Subsurface Biosphere and its Substrates Along a One-Million-Year Ferruginous Lake Archive DOI Creative Commons
Fátima Ruiz-Blas, André Friese, Alexander Bartholomäus

et al.

Microbial Ecology, Journal Year: 2025, Volume and Issue: 88(1)

Published: June 3, 2025

Lake Towuti, Indonesia, is an ancient stratified lake with ferruginous (iron-rich, sulfate-poor) anoxic bottom water conditions and a long depositional record affected by redox changes in the column sediments. As modern analogue of Earth's early oceans, it enables study active microbial subsurface biosphere its role organic matter iron mineralization. Combining 16S rRNA genes, cell counts, pore geochemistry, bulk sediment profiles from 100-m-long core, we present first comprehensive characterization deep along one-million-year lacustrine archive. Electron acceptors became depleted at shallow depths, resulting drastic decrease densities fermentative zone, where Bathyarchaeia dominate community composition. Although alpha beta diversity reflected initial depletion substrates during burial, they also varied across successive lithologies, indicating that composition subsequent to deposition affects diversity. The upper sediments (0-20 mblf) sheltered dense diverse involved remineralization, actively producing converting volatile fatty acids into carbon dioxide methane. Deeper (20-70 contained low-diversity communities adapted nutrient scarcity. In contrast, deepest (70-100 increased reflecting greater availability terrestrial origin. Despite being prime constituents biosphere, gene was observed discrete layers (tephra, diatom ooze, peat). This demonstrated remained traceable, while drove reductive diagenesis.

Language: Английский

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