Macroalgae degradation promotes microbial iron reduction via electron shuttling in coastal Antarctic sediments
Colonization of newly ice-free areas by marine benthic organisms intensifies burial of macroalgae detritus in Potter Cove coastal surface sediments (Western Antarctic Peninsula). Thus, fresh and labile macroalgal detritus serves as primary organic matter (OM) source for microbial degradation. Here,...
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ftdoajarticles:oai:doaj.org/article:9f76c8b9bbe34b96a60d70a011aeaa43 2023-05-15T13:48:18+02:00 Macroalgae degradation promotes microbial iron reduction via electron shuttling in coastal Antarctic sediments David A. Aromokeye Graciana Willis-Poratti Lea C. Wunder Xiuran Yin Jenny Wendt Tim Richter-Heitmann Susann Henkel Susana Vázquez Marcus Elvert Walter Mac Cormack Michael W. Friedrich 2021-11-01T00:00:00Z https://doi.org/10.1016/j.envint.2021.106602 https://doaj.org/article/9f76c8b9bbe34b96a60d70a011aeaa43 EN eng Elsevier http://www.sciencedirect.com/science/article/pii/S0160412021002270 https://doaj.org/toc/0160-4120 0160-4120 doi:10.1016/j.envint.2021.106602 https://doaj.org/article/9f76c8b9bbe34b96a60d70a011aeaa43 Environment International, Vol 156, Iss , Pp 106602- (2021) Microbial iron-reduction Marine sediments Organic matter degradation Climate change Antarctica Environmental sciences GE1-350 article 2021 ftdoajarticles https://doi.org/10.1016/j.envint.2021.106602 2022-12-31T05:58:43Z Colonization of newly ice-free areas by marine benthic organisms intensifies burial of macroalgae detritus in Potter Cove coastal surface sediments (Western Antarctic Peninsula). Thus, fresh and labile macroalgal detritus serves as primary organic matter (OM) source for microbial degradation. Here, we investigated the effects on post-depositional microbial iron reduction in Potter Cove using sediment incubations amended with pulverized macroalgal detritus as OM source, acetate as primary product of OM degradation and lepidocrocite as reactive iron oxide to mimic in situ conditions. Humic substances analogue anthraquinone-2,6-disulfonic acid (AQDS) was also added to some treatments to simulate potential for electron shuttling. Microbial iron reduction was promoted by macroalgae and further enhanced by up to 30-folds with AQDS. Notably, while acetate amendment alone did not stimulate iron reduction, adding macroalgae alone did. Acetate, formate, lactate, butyrate and propionate were detected as fermentation products from macroalgae degradation. By combining 16S rRNA gene sequencing and RNA stable isotope probing, we reconstructed the potential microbial food chain from macroalgae degraders to iron reducers. Psychromonas, Marinifilum, Moritella, and Colwellia were detected as potential fermenters of macroalgae and fermentation products such as lactate. Members of class deltaproteobacteria including Sva1033, Desulfuromonas, and Desulfuromusa together with Arcobacter (former phylum Epsilonbacteraeota, now Campylobacterota) acted as dissimilatory iron reducers. Our findings demonstrate that increasing burial of macroalgal detritus in an Antarctic fjord affected by glacier retreat intensifies early diagenetic processes such as iron reduction. Under scenarios of global warming, the active microbial populations identified above will expand their environmental function, facilitate OM remineralisation, and contribute to an increased release of iron and CO2 from sediments. Such indirect consequences of glacial retreat are ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica Directory of Open Access Journals: DOAJ Articles Antarctic Antarctic Peninsula Potter Cove Environment International 156 106602 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Microbial iron-reduction Marine sediments Organic matter degradation Climate change Antarctica Environmental sciences GE1-350 |
spellingShingle |
Microbial iron-reduction Marine sediments Organic matter degradation Climate change Antarctica Environmental sciences GE1-350 David A. Aromokeye Graciana Willis-Poratti Lea C. Wunder Xiuran Yin Jenny Wendt Tim Richter-Heitmann Susann Henkel Susana Vázquez Marcus Elvert Walter Mac Cormack Michael W. Friedrich Macroalgae degradation promotes microbial iron reduction via electron shuttling in coastal Antarctic sediments |
topic_facet |
Microbial iron-reduction Marine sediments Organic matter degradation Climate change Antarctica Environmental sciences GE1-350 |
description |
Colonization of newly ice-free areas by marine benthic organisms intensifies burial of macroalgae detritus in Potter Cove coastal surface sediments (Western Antarctic Peninsula). Thus, fresh and labile macroalgal detritus serves as primary organic matter (OM) source for microbial degradation. Here, we investigated the effects on post-depositional microbial iron reduction in Potter Cove using sediment incubations amended with pulverized macroalgal detritus as OM source, acetate as primary product of OM degradation and lepidocrocite as reactive iron oxide to mimic in situ conditions. Humic substances analogue anthraquinone-2,6-disulfonic acid (AQDS) was also added to some treatments to simulate potential for electron shuttling. Microbial iron reduction was promoted by macroalgae and further enhanced by up to 30-folds with AQDS. Notably, while acetate amendment alone did not stimulate iron reduction, adding macroalgae alone did. Acetate, formate, lactate, butyrate and propionate were detected as fermentation products from macroalgae degradation. By combining 16S rRNA gene sequencing and RNA stable isotope probing, we reconstructed the potential microbial food chain from macroalgae degraders to iron reducers. Psychromonas, Marinifilum, Moritella, and Colwellia were detected as potential fermenters of macroalgae and fermentation products such as lactate. Members of class deltaproteobacteria including Sva1033, Desulfuromonas, and Desulfuromusa together with Arcobacter (former phylum Epsilonbacteraeota, now Campylobacterota) acted as dissimilatory iron reducers. Our findings demonstrate that increasing burial of macroalgal detritus in an Antarctic fjord affected by glacier retreat intensifies early diagenetic processes such as iron reduction. Under scenarios of global warming, the active microbial populations identified above will expand their environmental function, facilitate OM remineralisation, and contribute to an increased release of iron and CO2 from sediments. Such indirect consequences of glacial retreat are ... |
format |
Article in Journal/Newspaper |
author |
David A. Aromokeye Graciana Willis-Poratti Lea C. Wunder Xiuran Yin Jenny Wendt Tim Richter-Heitmann Susann Henkel Susana Vázquez Marcus Elvert Walter Mac Cormack Michael W. Friedrich |
author_facet |
David A. Aromokeye Graciana Willis-Poratti Lea C. Wunder Xiuran Yin Jenny Wendt Tim Richter-Heitmann Susann Henkel Susana Vázquez Marcus Elvert Walter Mac Cormack Michael W. Friedrich |
author_sort |
David A. Aromokeye |
title |
Macroalgae degradation promotes microbial iron reduction via electron shuttling in coastal Antarctic sediments |
title_short |
Macroalgae degradation promotes microbial iron reduction via electron shuttling in coastal Antarctic sediments |
title_full |
Macroalgae degradation promotes microbial iron reduction via electron shuttling in coastal Antarctic sediments |
title_fullStr |
Macroalgae degradation promotes microbial iron reduction via electron shuttling in coastal Antarctic sediments |
title_full_unstemmed |
Macroalgae degradation promotes microbial iron reduction via electron shuttling in coastal Antarctic sediments |
title_sort |
macroalgae degradation promotes microbial iron reduction via electron shuttling in coastal antarctic sediments |
publisher |
Elsevier |
publishDate |
2021 |
url |
https://doi.org/10.1016/j.envint.2021.106602 https://doaj.org/article/9f76c8b9bbe34b96a60d70a011aeaa43 |
geographic |
Antarctic Antarctic Peninsula Potter Cove |
geographic_facet |
Antarctic Antarctic Peninsula Potter Cove |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica |
op_source |
Environment International, Vol 156, Iss , Pp 106602- (2021) |
op_relation |
http://www.sciencedirect.com/science/article/pii/S0160412021002270 https://doaj.org/toc/0160-4120 0160-4120 doi:10.1016/j.envint.2021.106602 https://doaj.org/article/9f76c8b9bbe34b96a60d70a011aeaa43 |
op_doi |
https://doi.org/10.1016/j.envint.2021.106602 |
container_title |
Environment International |
container_volume |
156 |
container_start_page |
106602 |
_version_ |
1766249083188543488 |