Modeled energetics of bacterial communities in ancient subzero brines
Cryopeg brines are isolated volumes of hypersaline water in subzero permafrost. The cryopeg system at Utqiaġvik, Alaska, is estimated to date back to 40 ka BP or earlier, a remnant of a late Pleistocene Ocean. Surprisingly, the cryopeg brines contain high concentrations of organic carbon, including...
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ftdoajarticles:oai:doaj.org/article:99e346af96b641cbaf5d2d953d9d1aaa 2024-02-11T10:01:45+01:00 Modeled energetics of bacterial communities in ancient subzero brines Georges Kanaan Tori M. Hoehler Go Iwahana Jody W. Deming 2023-07-01T00:00:00Z https://doi.org/10.3389/fmicb.2023.1206641 https://doaj.org/article/99e346af96b641cbaf5d2d953d9d1aaa EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fmicb.2023.1206641/full https://doaj.org/toc/1664-302X 1664-302X doi:10.3389/fmicb.2023.1206641 https://doaj.org/article/99e346af96b641cbaf5d2d953d9d1aaa Frontiers in Microbiology, Vol 14 (2023) cryopeg Arctic extremophiles permafrost maintenance energy Microbiology QR1-502 article 2023 ftdoajarticles https://doi.org/10.3389/fmicb.2023.1206641 2024-01-14T01:39:28Z Cryopeg brines are isolated volumes of hypersaline water in subzero permafrost. The cryopeg system at Utqiaġvik, Alaska, is estimated to date back to 40 ka BP or earlier, a remnant of a late Pleistocene Ocean. Surprisingly, the cryopeg brines contain high concentrations of organic carbon, including extracellular polysaccharides, and high densities of bacteria. How can these physiologically extreme, old, and geologically isolated systems support such an ecosystem? This study addresses this question by examining the energetics of the Utqiaġvik cryopeg brine ecosystem. Using literature-derived assumptions and new measurements on archived borehole materials, we first estimated the quantity of organic carbon when the system formed. We then considered two bacterial growth trajectories to calculate the lower and upper bounds of the cell-specific metabolic rate of these communities. These bounds represent the first community estimates of metabolic rate in a subzero hypersaline environment. To assess the plausibility of the different growth trajectories, we developed a model of the organic carbon cycle and applied it to three borehole scenarios. We also used dissolved inorganic carbon and nitrogen measurements to independently estimate the metabolic rate. The model reconstructs the growth trajectory of the microbial community and predicts the present-day cell density and organic carbon content. Model input included measured rates of the in-situ enzymatic conversion of particulate to dissolved organic carbon under subzero brine conditions. A sensitivity analysis of model parameters was performed, revealing an interplay between growth rate, cell-specific metabolic rate, and extracellular enzyme activity. This approach allowed us to identify plausible growth trajectories consistent with the observed bacterial densities in the cryopeg brines. We found that the cell-specific metabolic rate in this system is relatively high compared to marine sediments. We attribute this finding to the need to invest energy in the production ... Article in Journal/Newspaper Arctic permafrost Alaska Directory of Open Access Journals: DOAJ Articles Arctic Frontiers in Microbiology 14 |
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cryopeg Arctic extremophiles permafrost maintenance energy Microbiology QR1-502 |
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cryopeg Arctic extremophiles permafrost maintenance energy Microbiology QR1-502 Georges Kanaan Tori M. Hoehler Go Iwahana Jody W. Deming Modeled energetics of bacterial communities in ancient subzero brines |
topic_facet |
cryopeg Arctic extremophiles permafrost maintenance energy Microbiology QR1-502 |
description |
Cryopeg brines are isolated volumes of hypersaline water in subzero permafrost. The cryopeg system at Utqiaġvik, Alaska, is estimated to date back to 40 ka BP or earlier, a remnant of a late Pleistocene Ocean. Surprisingly, the cryopeg brines contain high concentrations of organic carbon, including extracellular polysaccharides, and high densities of bacteria. How can these physiologically extreme, old, and geologically isolated systems support such an ecosystem? This study addresses this question by examining the energetics of the Utqiaġvik cryopeg brine ecosystem. Using literature-derived assumptions and new measurements on archived borehole materials, we first estimated the quantity of organic carbon when the system formed. We then considered two bacterial growth trajectories to calculate the lower and upper bounds of the cell-specific metabolic rate of these communities. These bounds represent the first community estimates of metabolic rate in a subzero hypersaline environment. To assess the plausibility of the different growth trajectories, we developed a model of the organic carbon cycle and applied it to three borehole scenarios. We also used dissolved inorganic carbon and nitrogen measurements to independently estimate the metabolic rate. The model reconstructs the growth trajectory of the microbial community and predicts the present-day cell density and organic carbon content. Model input included measured rates of the in-situ enzymatic conversion of particulate to dissolved organic carbon under subzero brine conditions. A sensitivity analysis of model parameters was performed, revealing an interplay between growth rate, cell-specific metabolic rate, and extracellular enzyme activity. This approach allowed us to identify plausible growth trajectories consistent with the observed bacterial densities in the cryopeg brines. We found that the cell-specific metabolic rate in this system is relatively high compared to marine sediments. We attribute this finding to the need to invest energy in the production ... |
format |
Article in Journal/Newspaper |
author |
Georges Kanaan Tori M. Hoehler Go Iwahana Jody W. Deming |
author_facet |
Georges Kanaan Tori M. Hoehler Go Iwahana Jody W. Deming |
author_sort |
Georges Kanaan |
title |
Modeled energetics of bacterial communities in ancient subzero brines |
title_short |
Modeled energetics of bacterial communities in ancient subzero brines |
title_full |
Modeled energetics of bacterial communities in ancient subzero brines |
title_fullStr |
Modeled energetics of bacterial communities in ancient subzero brines |
title_full_unstemmed |
Modeled energetics of bacterial communities in ancient subzero brines |
title_sort |
modeled energetics of bacterial communities in ancient subzero brines |
publisher |
Frontiers Media S.A. |
publishDate |
2023 |
url |
https://doi.org/10.3389/fmicb.2023.1206641 https://doaj.org/article/99e346af96b641cbaf5d2d953d9d1aaa |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic permafrost Alaska |
genre_facet |
Arctic permafrost Alaska |
op_source |
Frontiers in Microbiology, Vol 14 (2023) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fmicb.2023.1206641/full https://doaj.org/toc/1664-302X 1664-302X doi:10.3389/fmicb.2023.1206641 https://doaj.org/article/99e346af96b641cbaf5d2d953d9d1aaa |
op_doi |
https://doi.org/10.3389/fmicb.2023.1206641 |
container_title |
Frontiers in Microbiology |
container_volume |
14 |
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1790597560690278400 |