Following the kinetics: iron-oxidizing microbial mats in cold Icelandic volcanic habitats and their rock-associated carbonaceous signature
Icelandic streams with mean annual temperatures of less than 5°C, which receive the cationic products of basaltic rock weathering, were found to host mats of iron-cycling microorganisms. We investigated two representative sites. Iron-oxidizing Gallionella and iron-reducing Geobacter species were pre...
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ftopenunivgb:oai:oro.open.ac.uk:41347 2023-06-11T04:13:12+02:00 Following the kinetics: iron-oxidizing microbial mats in cold Icelandic volcanic habitats and their rock-associated carbonaceous signature Cockell, Charles S. Kelly, Laura C. Summers, Stephen Marteinsson, Viggo 2011 https://oro.open.ac.uk/41347/ https://doi.org/10.1089/ast.2011.0606 unknown Cockell, Charles S.; Kelly, Laura C.; Summers, Stephen <http://oro.open.ac.uk/view/person/ss29877.html> and Marteinsson, Viggo (2011). Following the kinetics: iron-oxidizing microbial mats in cold Icelandic volcanic habitats and their rock-associated carbonaceous signature. Astrobiology, 11(7) pp. 679–694. Journal Item None PeerReviewed 2011 ftopenunivgb https://doi.org/10.1089/ast.2011.0606 2023-05-28T05:51:54Z Icelandic streams with mean annual temperatures of less than 5°C, which receive the cationic products of basaltic rock weathering, were found to host mats of iron-cycling microorganisms. We investigated two representative sites. Iron-oxidizing Gallionella and iron-reducing Geobacter species were present. The mats host a high bacterial diversity as determined by culture-independent methods. β -Proteobacteria, Actinobacteria, α - Proteobacteria, and Bacteroidetes were abundant microbial taxa. The mat contained a high number of phototroph sequences. The carbon compounds in the mat displayed broad G and D bands with Raman spectroscopy. This signature becomes incorporated into the weathered oxidized surface layer of the basaltic rocks and was observed on rocks that no longer host mats. The presence of iron-oxidizing taxa in the stream microbial mats, and the lack of them in previously studied volcanic rocks in Iceland that have intermittently been exposed to surface water flows, can be explained by the kinetic limitations to the extraction of reduced iron from rocks. This type of ecosystem illustrates key factors that control the distribution of chemolithotrophs in cold volcanic environments. The data show that one promising sample type for which the hypothesis of the existence of past life on Mars can be tested is the surface of volcanic rocks that, previously, were situated within channels carved by flowing water. Our results also show that the carbonaceous signatures of life, if life had occurred, could be found in or on these rocks. Article in Journal/Newspaper Iceland The Open University: Open Research Online (ORO) Astrobiology 11 7 679 694 |
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The Open University: Open Research Online (ORO) |
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Icelandic streams with mean annual temperatures of less than 5°C, which receive the cationic products of basaltic rock weathering, were found to host mats of iron-cycling microorganisms. We investigated two representative sites. Iron-oxidizing Gallionella and iron-reducing Geobacter species were present. The mats host a high bacterial diversity as determined by culture-independent methods. β -Proteobacteria, Actinobacteria, α - Proteobacteria, and Bacteroidetes were abundant microbial taxa. The mat contained a high number of phototroph sequences. The carbon compounds in the mat displayed broad G and D bands with Raman spectroscopy. This signature becomes incorporated into the weathered oxidized surface layer of the basaltic rocks and was observed on rocks that no longer host mats. The presence of iron-oxidizing taxa in the stream microbial mats, and the lack of them in previously studied volcanic rocks in Iceland that have intermittently been exposed to surface water flows, can be explained by the kinetic limitations to the extraction of reduced iron from rocks. This type of ecosystem illustrates key factors that control the distribution of chemolithotrophs in cold volcanic environments. The data show that one promising sample type for which the hypothesis of the existence of past life on Mars can be tested is the surface of volcanic rocks that, previously, were situated within channels carved by flowing water. Our results also show that the carbonaceous signatures of life, if life had occurred, could be found in or on these rocks. |
format |
Article in Journal/Newspaper |
author |
Cockell, Charles S. Kelly, Laura C. Summers, Stephen Marteinsson, Viggo |
spellingShingle |
Cockell, Charles S. Kelly, Laura C. Summers, Stephen Marteinsson, Viggo Following the kinetics: iron-oxidizing microbial mats in cold Icelandic volcanic habitats and their rock-associated carbonaceous signature |
author_facet |
Cockell, Charles S. Kelly, Laura C. Summers, Stephen Marteinsson, Viggo |
author_sort |
Cockell, Charles S. |
title |
Following the kinetics: iron-oxidizing microbial mats in cold Icelandic volcanic habitats and their rock-associated carbonaceous signature |
title_short |
Following the kinetics: iron-oxidizing microbial mats in cold Icelandic volcanic habitats and their rock-associated carbonaceous signature |
title_full |
Following the kinetics: iron-oxidizing microbial mats in cold Icelandic volcanic habitats and their rock-associated carbonaceous signature |
title_fullStr |
Following the kinetics: iron-oxidizing microbial mats in cold Icelandic volcanic habitats and their rock-associated carbonaceous signature |
title_full_unstemmed |
Following the kinetics: iron-oxidizing microbial mats in cold Icelandic volcanic habitats and their rock-associated carbonaceous signature |
title_sort |
following the kinetics: iron-oxidizing microbial mats in cold icelandic volcanic habitats and their rock-associated carbonaceous signature |
publishDate |
2011 |
url |
https://oro.open.ac.uk/41347/ https://doi.org/10.1089/ast.2011.0606 |
genre |
Iceland |
genre_facet |
Iceland |
op_relation |
Cockell, Charles S.; Kelly, Laura C.; Summers, Stephen <http://oro.open.ac.uk/view/person/ss29877.html> and Marteinsson, Viggo (2011). Following the kinetics: iron-oxidizing microbial mats in cold Icelandic volcanic habitats and their rock-associated carbonaceous signature. Astrobiology, 11(7) pp. 679–694. |
op_doi |
https://doi.org/10.1089/ast.2011.0606 |
container_title |
Astrobiology |
container_volume |
11 |
container_issue |
7 |
container_start_page |
679 |
op_container_end_page |
694 |
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1768389926613680128 |