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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ftpubmed:oai:pubmedcentral.nih.gov:10411740 2023-09-05T13:22:34+02:00 Modeled energetics of bacterial communities in ancient subzero brines Kanaan, Georges Hoehler, Tori M. Iwahana, Go Deming, Jody W. 2023-07-26 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10411740/ https://doi.org/10.3389/fmicb.2023.1206641 en eng Frontiers Media S.A. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10411740/ http://dx.doi.org/10.3389/fmicb.2023.1206641 Copyright © 2023 Kanaan, Hoehler, Iwahana and Deming. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Front Microbiol Microbiology Text 2023 ftpubmed https://doi.org/10.3389/fmicb.2023.1206641 2023-08-13T01:10:34Z 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 ... Text permafrost Alaska PubMed Central (PMC) Frontiers in Microbiology 14 |
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Microbiology Kanaan, Georges Hoehler, Tori M. Iwahana, Go Deming, Jody W. Modeled energetics of bacterial communities in ancient subzero brines |
topic_facet |
Microbiology |
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 |
Text |
author |
Kanaan, Georges Hoehler, Tori M. Iwahana, Go Deming, Jody W. |
author_facet |
Kanaan, Georges Hoehler, Tori M. Iwahana, Go Deming, Jody W. |
author_sort |
Kanaan, Georges |
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 |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10411740/ https://doi.org/10.3389/fmicb.2023.1206641 |
genre |
permafrost Alaska |
genre_facet |
permafrost Alaska |
op_source |
Front Microbiol |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10411740/ http://dx.doi.org/10.3389/fmicb.2023.1206641 |
op_rights |
Copyright © 2023 Kanaan, Hoehler, Iwahana and Deming. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
op_doi |
https://doi.org/10.3389/fmicb.2023.1206641 |
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Frontiers in Microbiology |
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14 |
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