Extracellular Electron Transfer May Be an Overlooked Contribution to Pelagic Respiration in Humic-Rich Freshwater Lakes
ABSTRACT Humic lakes and ponds receive large amounts of terrestrial carbon and are important components of the global carbon cycle, yet how their redox cycling influences the carbon budget is not fully understood. Here we compared metagenomes obtained from a humic bog and a clear-water eutrophic lak...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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American Society for Microbiology
2019-02-01
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| Series: | mSphere |
| Subjects: | |
| Online Access: | https://journals.asm.org/doi/10.1128/mSphere.00436-18 |
| _version_ | 1818399053643251712 |
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| author | Shaomei He Maximilian P. Lau Alexandra M. Linz Eric E. Roden Katherine D. McMahon |
| author_facet | Shaomei He Maximilian P. Lau Alexandra M. Linz Eric E. Roden Katherine D. McMahon |
| author_sort | Shaomei He |
| collection | DOAJ |
| description | ABSTRACT Humic lakes and ponds receive large amounts of terrestrial carbon and are important components of the global carbon cycle, yet how their redox cycling influences the carbon budget is not fully understood. Here we compared metagenomes obtained from a humic bog and a clear-water eutrophic lake and found a much larger number of genes that might be involved in extracellular electron transfer (EET) for iron redox reactions and humic substance (HS) reduction in the bog than in the clear-water lake, consistent with the much higher iron and HS levels in the bog. These genes were particularly rich in the bog’s anoxic hypolimnion and were found in diverse bacterial lineages, some of which are relatives of known iron oxidizers or iron-HS reducers. We hypothesize that HS may be a previously overlooked electron acceptor and that EET-enabled redox cycling may be important in pelagic respiration and greenhouse gas budget in humic-rich freshwater lakes. |
| first_indexed | 2024-12-14T07:14:34Z |
| format | Article |
| id | doaj.art-6bfbef21714142578feacede273af345 |
| institution | Directory Open Access Journal |
| issn | 2379-5042 |
| language | English |
| last_indexed | 2024-12-14T07:14:34Z |
| publishDate | 2019-02-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | mSphere |
| spelling | doaj.art-6bfbef21714142578feacede273af3452022-12-21T23:11:44ZengAmerican Society for MicrobiologymSphere2379-50422019-02-014110.1128/mSphere.00436-18Extracellular Electron Transfer May Be an Overlooked Contribution to Pelagic Respiration in Humic-Rich Freshwater LakesShaomei He0Maximilian P. Lau1Alexandra M. Linz2Eric E. Roden3Katherine D. McMahon4Department of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin, USADépartement des Sciences Biologiques, Université du Québec à Montréal (UQAM), Montréal, Quebec, CanadaDepartment of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin, USADepartment of Geoscience, University of Wisconsin—Madison, Madison, Wisconsin, USADepartment of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin, USAABSTRACT Humic lakes and ponds receive large amounts of terrestrial carbon and are important components of the global carbon cycle, yet how their redox cycling influences the carbon budget is not fully understood. Here we compared metagenomes obtained from a humic bog and a clear-water eutrophic lake and found a much larger number of genes that might be involved in extracellular electron transfer (EET) for iron redox reactions and humic substance (HS) reduction in the bog than in the clear-water lake, consistent with the much higher iron and HS levels in the bog. These genes were particularly rich in the bog’s anoxic hypolimnion and were found in diverse bacterial lineages, some of which are relatives of known iron oxidizers or iron-HS reducers. We hypothesize that HS may be a previously overlooked electron acceptor and that EET-enabled redox cycling may be important in pelagic respiration and greenhouse gas budget in humic-rich freshwater lakes.https://journals.asm.org/doi/10.1128/mSphere.00436-18Cyc2extracellular electron transferEEThumic lakehumic substancesHS |
| spellingShingle | Shaomei He Maximilian P. Lau Alexandra M. Linz Eric E. Roden Katherine D. McMahon Extracellular Electron Transfer May Be an Overlooked Contribution to Pelagic Respiration in Humic-Rich Freshwater Lakes mSphere Cyc2 extracellular electron transfer EET humic lake humic substances HS |
| title | Extracellular Electron Transfer May Be an Overlooked Contribution to Pelagic Respiration in Humic-Rich Freshwater Lakes |
| title_full | Extracellular Electron Transfer May Be an Overlooked Contribution to Pelagic Respiration in Humic-Rich Freshwater Lakes |
| title_fullStr | Extracellular Electron Transfer May Be an Overlooked Contribution to Pelagic Respiration in Humic-Rich Freshwater Lakes |
| title_full_unstemmed | Extracellular Electron Transfer May Be an Overlooked Contribution to Pelagic Respiration in Humic-Rich Freshwater Lakes |
| title_short | Extracellular Electron Transfer May Be an Overlooked Contribution to Pelagic Respiration in Humic-Rich Freshwater Lakes |
| title_sort | extracellular electron transfer may be an overlooked contribution to pelagic respiration in humic rich freshwater lakes |
| topic | Cyc2 extracellular electron transfer EET humic lake humic substances HS |
| url | https://journals.asm.org/doi/10.1128/mSphere.00436-18 |
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