Microbial Iron Oxidation in the Arctic Tundra and Its Implications for Biogeochemical Cycling
ABSTRACT The role that neutrophilic iron-oxidizing bacteria play in the Arctic tundra is unknown. This study surveyed chemosynthetic iron-oxidizing communities at the North Slope of Alaska near Toolik Field Station (TFS) at Toolik Lake (lat 68.63, long −149.60). Microbial iron mats were common in su...
Published in: | Applied and Environmental Microbiology |
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Online Access: | http://dx.doi.org/10.1128/aem.02832-15 https://journals.asm.org/doi/pdf/10.1128/AEM.02832-15 |
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crasmicro:10.1128/aem.02832-15 2024-06-23T07:50:16+00:00 Microbial Iron Oxidation in the Arctic Tundra and Its Implications for Biogeochemical Cycling Emerson, David Scott, Jarrod J. Benes, Joshua Bowden, William B. Löffler, F. E. 2015 http://dx.doi.org/10.1128/aem.02832-15 https://journals.asm.org/doi/pdf/10.1128/AEM.02832-15 en eng American Society for Microbiology https://journals.asm.org/non-commercial-tdm-license Applied and Environmental Microbiology volume 81, issue 23, page 8066-8075 ISSN 0099-2240 1098-5336 journal-article 2015 crasmicro https://doi.org/10.1128/aem.02832-15 2024-06-03T08:11:11Z ABSTRACT The role that neutrophilic iron-oxidizing bacteria play in the Arctic tundra is unknown. This study surveyed chemosynthetic iron-oxidizing communities at the North Slope of Alaska near Toolik Field Station (TFS) at Toolik Lake (lat 68.63, long −149.60). Microbial iron mats were common in submerged habitats with stationary or slowly flowing water, and their greatest areal extent is in coating plant stems and sediments in wet sedge meadows. Some Fe-oxidizing bacteria (FeOB) produce easily recognized sheath or stalk morphotypes that were present and dominant in all the mats we observed. The cool water temperatures (9 to 11°C) and reduced pH (5.0 to 6.6) at all sites kinetically favor microbial iron oxidation. A microbial survey of five sites based on 16S rRNA genes found a predominance of Proteobacteria , with Betaproteobacteria and members of the family Comamonadaceae being the most prevalent operational taxonomic units (OTUs). In relative abundance, clades of lithotrophic FeOB composed 5 to 10% of the communities. OTUs related to cyanobacteria and chloroplasts accounted for 3 to 25% of the communities. Oxygen profiles showed evidence for oxygenic photosynthesis at the surface of some mats, indicating the coexistence of photosynthetic and FeOB populations. The relative abundance of OTUs belonging to putative Fe-reducing bacteria (FeRB) averaged around 11% in the sampled iron mats. Mats incubated anaerobically with 10 mM acetate rapidly initiated Fe reduction, indicating that active iron cycling is likely. The prevalence of iron mats on the tundra might impact the carbon cycle through lithoautotrophic chemosynthesis, anaerobic respiration of organic carbon coupled to iron reduction, and the suppression of methanogenesis, and it potentially influences phosphorus dynamics through the adsorption of phosphorus to iron oxides. Article in Journal/Newspaper Arctic north slope Tundra Alaska ASM Journals (American Society for Microbiology) Arctic Applied and Environmental Microbiology 81 23 8066 8075 |
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Open Polar |
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ASM Journals (American Society for Microbiology) |
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crasmicro |
language |
English |
description |
ABSTRACT The role that neutrophilic iron-oxidizing bacteria play in the Arctic tundra is unknown. This study surveyed chemosynthetic iron-oxidizing communities at the North Slope of Alaska near Toolik Field Station (TFS) at Toolik Lake (lat 68.63, long −149.60). Microbial iron mats were common in submerged habitats with stationary or slowly flowing water, and their greatest areal extent is in coating plant stems and sediments in wet sedge meadows. Some Fe-oxidizing bacteria (FeOB) produce easily recognized sheath or stalk morphotypes that were present and dominant in all the mats we observed. The cool water temperatures (9 to 11°C) and reduced pH (5.0 to 6.6) at all sites kinetically favor microbial iron oxidation. A microbial survey of five sites based on 16S rRNA genes found a predominance of Proteobacteria , with Betaproteobacteria and members of the family Comamonadaceae being the most prevalent operational taxonomic units (OTUs). In relative abundance, clades of lithotrophic FeOB composed 5 to 10% of the communities. OTUs related to cyanobacteria and chloroplasts accounted for 3 to 25% of the communities. Oxygen profiles showed evidence for oxygenic photosynthesis at the surface of some mats, indicating the coexistence of photosynthetic and FeOB populations. The relative abundance of OTUs belonging to putative Fe-reducing bacteria (FeRB) averaged around 11% in the sampled iron mats. Mats incubated anaerobically with 10 mM acetate rapidly initiated Fe reduction, indicating that active iron cycling is likely. The prevalence of iron mats on the tundra might impact the carbon cycle through lithoautotrophic chemosynthesis, anaerobic respiration of organic carbon coupled to iron reduction, and the suppression of methanogenesis, and it potentially influences phosphorus dynamics through the adsorption of phosphorus to iron oxides. |
author2 |
Löffler, F. E. |
format |
Article in Journal/Newspaper |
author |
Emerson, David Scott, Jarrod J. Benes, Joshua Bowden, William B. |
spellingShingle |
Emerson, David Scott, Jarrod J. Benes, Joshua Bowden, William B. Microbial Iron Oxidation in the Arctic Tundra and Its Implications for Biogeochemical Cycling |
author_facet |
Emerson, David Scott, Jarrod J. Benes, Joshua Bowden, William B. |
author_sort |
Emerson, David |
title |
Microbial Iron Oxidation in the Arctic Tundra and Its Implications for Biogeochemical Cycling |
title_short |
Microbial Iron Oxidation in the Arctic Tundra and Its Implications for Biogeochemical Cycling |
title_full |
Microbial Iron Oxidation in the Arctic Tundra and Its Implications for Biogeochemical Cycling |
title_fullStr |
Microbial Iron Oxidation in the Arctic Tundra and Its Implications for Biogeochemical Cycling |
title_full_unstemmed |
Microbial Iron Oxidation in the Arctic Tundra and Its Implications for Biogeochemical Cycling |
title_sort |
microbial iron oxidation in the arctic tundra and its implications for biogeochemical cycling |
publisher |
American Society for Microbiology |
publishDate |
2015 |
url |
http://dx.doi.org/10.1128/aem.02832-15 https://journals.asm.org/doi/pdf/10.1128/AEM.02832-15 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic north slope Tundra Alaska |
genre_facet |
Arctic north slope Tundra Alaska |
op_source |
Applied and Environmental Microbiology volume 81, issue 23, page 8066-8075 ISSN 0099-2240 1098-5336 |
op_rights |
https://journals.asm.org/non-commercial-tdm-license |
op_doi |
https://doi.org/10.1128/aem.02832-15 |
container_title |
Applied and Environmental Microbiology |
container_volume |
81 |
container_issue |
23 |
container_start_page |
8066 |
op_container_end_page |
8075 |
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1802641135628189696 |