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| Roussel, Erwan; Cragg, Barry A.; Webster, Gordon; Sass, Henrik; Tang, Xiaohong; Williams, Angharad S.; Gorra, Roberta; Weightman, Andrew J.; Parkes, R. John. |
| The impact of temperature (0 - 80°C) on anaerobic biogeochemical processes and prokaryotic communities in marine sediments (tidal flat) was investigated in slurries for up to 100 days. Temperature had a non-linear effect on biogeochemistry and prokaryotes with rapid changes over small temperature intervals. Some activities (e.g. methanogenesis) had multiple “windows” within a large temperature range (~10 - 80°C). Others, including acetate oxidation, had maximum activities within a temperature zone, which varied with electron acceptor (metal oxide [up to ~34°C] and sulphate [up to ~50°C]). Substrates for sulphate reduction changed from predominantly acetate below, and H2 above, a 43°C critical temperature; along with changes in activation energies and types... |
| Tipo: Text |
Palavras-chave: Sediment; Temperature; Anaerobic processes; Chemoorganotrophic; Chemolithotrophic; Mineralisation; Sulphate reduction; Methanogenesis; Acetogenesis. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00273/38464/36883.pdf |
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| Parkes, Ronald John; Berlendis, Sabrina; Roussel, Erwan; Bahruji, Hasiliza; Webster, Gordon; Oldroyd, Anthony; Weightman, Andrew J.; Bowker, Michael; Davies, Philipp R; Sass, Henrik. |
| 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... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00483/59444/62283.pdf |
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| O'Sullivan, Louise A.; Roussel, Erwan; Weightman, Andrew J.; Webster, Gordon; Hubert, Casey R. J.; Bell, Emma; Head, Ian; Sass, Henrik; Parkes, R. John. |
| Bacterial spores are widespread in marine sediments, including those of thermophilic, sulphate-reducing bacteria, which have a high minimum growth temperature making it unlikely that they grow in situ. These Desulfotomaculum spp. are thought to be from hot environments and are distributed by ocean currents. Their cells and spores upper temperature limit for survival is unknown, as is whether they can survive repeated high-temperature exposure that might occur in hydrothermal systems. This was investigated by incubating estuarine sediments significantly above (40–80 °C) maximum in situ temperatures (~23 °C), and with and without prior triple autoclaving. Sulphate reduction occurred at 40–60 °C and at 60 °C was unaffected by autoclaving. Desulfotomaculum sp.... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00216/32759/31181.pdf |
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