Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake
Abstract Lacustrine microbial mats in A ntarctic ice‐free oases are considered modern analogues of early microbial ecosystems as their primary production is generally dominated by cyanobacteria, the heterotrophic food chain typically truncated due to extreme environmental conditions, and they are ge...
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crwiley:10.1111/gbi.12096 2024-10-13T14:01:31+00:00 Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake Lepot, K. Compère, P. Gérard, E. Namsaraev, Z. Verleyen, E. Tavernier, I. Hodgson, D. A. Vyverman, W. Gilbert, B. Wilmotte, A. Javaux, E. J. European Research Council Fonds De La Recherche Scientifique - FNRS Belgian Science Policy Office Belgian Science Policy Office Interuniversity Attraction Poles Fonds de la Recherche Fondamentale Collective (Belgium FNRS) Institute for the Promotion of Innovation through Science and Technology 2014 http://dx.doi.org/10.1111/gbi.12096 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fgbi.12096 https://onlinelibrary.wiley.com/doi/pdf/10.1111/gbi.12096 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Geobiology volume 12, issue 5, page 424-450 ISSN 1472-4677 1472-4669 journal-article 2014 crwiley https://doi.org/10.1111/gbi.12096 2024-09-17T04:46:10Z Abstract Lacustrine microbial mats in A ntarctic ice‐free oases are considered modern analogues of early microbial ecosystems as their primary production is generally dominated by cyanobacteria, the heterotrophic food chain typically truncated due to extreme environmental conditions, and they are geographically isolated. To better understand early fossilization and mineralization processes in this context, we studied the microstructure and chemistry of organo‐mineral associations in a suite of sediments 50–4530 cal. years old from a lake in S karvsnes, L ützow H olm B ay, E ast A ntarctica. First, we report an exceptional preservation of fossil autotrophs and their biomolecules on millennial timescales. The pigment scytonemin is preserved inside cyanobacterial sheaths. As non‐pigmented sheaths are also preserved, scytonemin likely played little role in the preservation of sheath polysaccharides, which have been cross‐linked by ether bonds. Coccoids preserved thylakoids and autofluorescence of pigments such as carotenoids. This exceptional preservation of autotrophs in the fossil mats argues for limited biodegradation during and after deposition. Moreover, cell‐shaped aggregates preserved sulfur‐rich nanoglobules, supporting fossilization of instable intracellular byproducts of chemotrophic or phototrophic S ‐oxidizers. Second, we report a diversity of micro‐ to nanostructured CaCO 3 precipitates intimately associated with extracellular polymeric substances, cyanobacteria, and/or other prokaryotes. Micro‐peloids T ype 1 display features that distinguish them from known carbonates crystallized in inorganic conditions: (i) Type 1 A are often filled with globular nanocarbonates and/or surrounded by a fibrous fringe, (ii) Type 1 B are empty and display ovoid to wrinkled fringes of nanocrystallites that can be radially oriented (fibrous or triangular) or multilayered, and (iii) all show small‐size variations. Type 2 rounded carbonates 1–2 μm in diameter occurring inside autofluorescent spheres interpreted as coccoidal ... Article in Journal/Newspaper Antarc* Antarctic Wiley Online Library Antarctic Geobiology 12 5 424 450 |
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Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Abstract Lacustrine microbial mats in A ntarctic ice‐free oases are considered modern analogues of early microbial ecosystems as their primary production is generally dominated by cyanobacteria, the heterotrophic food chain typically truncated due to extreme environmental conditions, and they are geographically isolated. To better understand early fossilization and mineralization processes in this context, we studied the microstructure and chemistry of organo‐mineral associations in a suite of sediments 50–4530 cal. years old from a lake in S karvsnes, L ützow H olm B ay, E ast A ntarctica. First, we report an exceptional preservation of fossil autotrophs and their biomolecules on millennial timescales. The pigment scytonemin is preserved inside cyanobacterial sheaths. As non‐pigmented sheaths are also preserved, scytonemin likely played little role in the preservation of sheath polysaccharides, which have been cross‐linked by ether bonds. Coccoids preserved thylakoids and autofluorescence of pigments such as carotenoids. This exceptional preservation of autotrophs in the fossil mats argues for limited biodegradation during and after deposition. Moreover, cell‐shaped aggregates preserved sulfur‐rich nanoglobules, supporting fossilization of instable intracellular byproducts of chemotrophic or phototrophic S ‐oxidizers. Second, we report a diversity of micro‐ to nanostructured CaCO 3 precipitates intimately associated with extracellular polymeric substances, cyanobacteria, and/or other prokaryotes. Micro‐peloids T ype 1 display features that distinguish them from known carbonates crystallized in inorganic conditions: (i) Type 1 A are often filled with globular nanocarbonates and/or surrounded by a fibrous fringe, (ii) Type 1 B are empty and display ovoid to wrinkled fringes of nanocrystallites that can be radially oriented (fibrous or triangular) or multilayered, and (iii) all show small‐size variations. Type 2 rounded carbonates 1–2 μm in diameter occurring inside autofluorescent spheres interpreted as coccoidal ... |
author2 |
European Research Council Fonds De La Recherche Scientifique - FNRS Belgian Science Policy Office Belgian Science Policy Office Interuniversity Attraction Poles Fonds de la Recherche Fondamentale Collective (Belgium FNRS) Institute for the Promotion of Innovation through Science and Technology |
format |
Article in Journal/Newspaper |
author |
Lepot, K. Compère, P. Gérard, E. Namsaraev, Z. Verleyen, E. Tavernier, I. Hodgson, D. A. Vyverman, W. Gilbert, B. Wilmotte, A. Javaux, E. J. |
spellingShingle |
Lepot, K. Compère, P. Gérard, E. Namsaraev, Z. Verleyen, E. Tavernier, I. Hodgson, D. A. Vyverman, W. Gilbert, B. Wilmotte, A. Javaux, E. J. Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake |
author_facet |
Lepot, K. Compère, P. Gérard, E. Namsaraev, Z. Verleyen, E. Tavernier, I. Hodgson, D. A. Vyverman, W. Gilbert, B. Wilmotte, A. Javaux, E. J. |
author_sort |
Lepot, K. |
title |
Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake |
title_short |
Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake |
title_full |
Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake |
title_fullStr |
Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake |
title_full_unstemmed |
Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake |
title_sort |
organic and mineral imprints in fossil photosynthetic mats of an east antarctic lake |
publisher |
Wiley |
publishDate |
2014 |
url |
http://dx.doi.org/10.1111/gbi.12096 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fgbi.12096 https://onlinelibrary.wiley.com/doi/pdf/10.1111/gbi.12096 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Geobiology volume 12, issue 5, page 424-450 ISSN 1472-4677 1472-4669 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/gbi.12096 |
container_title |
Geobiology |
container_volume |
12 |
container_issue |
5 |
container_start_page |
424 |
op_container_end_page |
450 |
_version_ |
1812811287021748224 |