Degradation state of organic matter in surface sediments from the Southern Beaufort Sea: a lipid approach
International audience Abstract. For the next decades significant climatic changes should occur in the Arctic zone. The expected destabilisation of permafrost and its consequences for hydrology and plant cover should increase the input of terrigenous carbon to coastal seas. Consequently, the relativ...
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Online Access: | https://hal.science/hal-00730371 https://hal.science/hal-00730371/document https://hal.science/hal-00730371/file/bg-9-3513-2012.pdf https://doi.org/10.5194/bg-9-3513-2012 |
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ftinsu:oai:HAL:hal-00730371v1 2023-12-31T10:03:41+01:00 Degradation state of organic matter in surface sediments from the Southern Beaufort Sea: a lipid approach Rontani, Jean-Francois Charrìère, Bruno Petit, Morgan Vaultier, Frederic Heipieper, Herman Link, Heike Chaillou, Gwenaelle Sempere, Richard Institut méditerranéen d'océanologie (MIO) Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS) Department of Environmental Biotechnology UFZ Leipzig Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ) Institut des Sciences de la MER de Rimouski (ISMER) Université du Québec à Rimouski (UQAR) Departement de Biologie, Chimie et Géographie 2012 https://hal.science/hal-00730371 https://hal.science/hal-00730371/document https://hal.science/hal-00730371/file/bg-9-3513-2012.pdf https://doi.org/10.5194/bg-9-3513-2012 en eng HAL CCSD European Geosciences Union info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-9-3513-2012 hal-00730371 https://hal.science/hal-00730371 https://hal.science/hal-00730371/document https://hal.science/hal-00730371/file/bg-9-3513-2012.pdf doi:10.5194/bg-9-3513-2012 http://creativecommons.org/licenses/by-nd/ info:eu-repo/semantics/OpenAccess ISSN: 1726-4170 EISSN: 1726-4189 Biogeosciences https://hal.science/hal-00730371 Biogeosciences, 2012, 9, pp.3513-3530. ⟨10.5194/bg-9-3513-2012⟩ [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere info:eu-repo/semantics/article Journal articles 2012 ftinsu https://doi.org/10.5194/bg-9-3513-2012 2023-12-06T17:25:51Z International audience Abstract. For the next decades significant climatic changes should occur in the Arctic zone. The expected destabilisation of permafrost and its consequences for hydrology and plant cover should increase the input of terrigenous carbon to coastal seas. Consequently, the relative importance of the fluxes of terrestrial and marine organic carbon to the seafloor will likely change, strongly impacting the preservation of organic carbon in Arctic marine sediments. Here, we investigated the lipid content of surface sediments collected on the Mackenzie basin in the Beaufort Sea. Particular attention was given to biotic and abiotic degradation products of sterols and monounsaturated fatty acids. By using sitosterol and campesterol degradation products as tracers of the degradation of terrestrial higher plant inputs and brassicasterol degradation products as tracers of degradation of phytoplanktonic organisms, it could be observed that autoxidation, photooxidation and biodegradation processes act much more intensively on higher plant debris than on phytoplanktonic organisms. Examination of oxidation products of monounsaturated fatty acids showed that photo- and autoxidation processes act more intensively on bacteria than on phytodetritus. Enhanced damages induced by singlet oxygen (transferred from senescent phytoplanktonic cells) in bacteria were attributed to the lack of an adapted antioxidant system in these microorganisms. The strong oxidative stress observed in the sampled sediments resulted in the production of significant amounts of epoxy acids and unusually high proportions of monounsaturated fatty acids with a trans double bond. The formation of epoxy acids was attributed to peroxygenases (enzymes playing a protective role against the deleterious effects of fatty acid hydroperoxides in vivo), while cis/trans isomerisation was probably induced by thiyl radicals produced during the reaction of thiols with hydroperoxides. Our results confirm the important role played by abiotic oxidative ... Article in Journal/Newspaper Arctic Beaufort Sea Mackenzie Basin permafrost Institut national des sciences de l'Univers: HAL-INSU Biogeosciences 9 9 3513 3530 |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere Rontani, Jean-Francois Charrìère, Bruno Petit, Morgan Vaultier, Frederic Heipieper, Herman Link, Heike Chaillou, Gwenaelle Sempere, Richard Degradation state of organic matter in surface sediments from the Southern Beaufort Sea: a lipid approach |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
description |
International audience Abstract. For the next decades significant climatic changes should occur in the Arctic zone. The expected destabilisation of permafrost and its consequences for hydrology and plant cover should increase the input of terrigenous carbon to coastal seas. Consequently, the relative importance of the fluxes of terrestrial and marine organic carbon to the seafloor will likely change, strongly impacting the preservation of organic carbon in Arctic marine sediments. Here, we investigated the lipid content of surface sediments collected on the Mackenzie basin in the Beaufort Sea. Particular attention was given to biotic and abiotic degradation products of sterols and monounsaturated fatty acids. By using sitosterol and campesterol degradation products as tracers of the degradation of terrestrial higher plant inputs and brassicasterol degradation products as tracers of degradation of phytoplanktonic organisms, it could be observed that autoxidation, photooxidation and biodegradation processes act much more intensively on higher plant debris than on phytoplanktonic organisms. Examination of oxidation products of monounsaturated fatty acids showed that photo- and autoxidation processes act more intensively on bacteria than on phytodetritus. Enhanced damages induced by singlet oxygen (transferred from senescent phytoplanktonic cells) in bacteria were attributed to the lack of an adapted antioxidant system in these microorganisms. The strong oxidative stress observed in the sampled sediments resulted in the production of significant amounts of epoxy acids and unusually high proportions of monounsaturated fatty acids with a trans double bond. The formation of epoxy acids was attributed to peroxygenases (enzymes playing a protective role against the deleterious effects of fatty acid hydroperoxides in vivo), while cis/trans isomerisation was probably induced by thiyl radicals produced during the reaction of thiols with hydroperoxides. Our results confirm the important role played by abiotic oxidative ... |
author2 |
Institut méditerranéen d'océanologie (MIO) Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS) Department of Environmental Biotechnology UFZ Leipzig Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ) Institut des Sciences de la MER de Rimouski (ISMER) Université du Québec à Rimouski (UQAR) Departement de Biologie, Chimie et Géographie |
format |
Article in Journal/Newspaper |
author |
Rontani, Jean-Francois Charrìère, Bruno Petit, Morgan Vaultier, Frederic Heipieper, Herman Link, Heike Chaillou, Gwenaelle Sempere, Richard |
author_facet |
Rontani, Jean-Francois Charrìère, Bruno Petit, Morgan Vaultier, Frederic Heipieper, Herman Link, Heike Chaillou, Gwenaelle Sempere, Richard |
author_sort |
Rontani, Jean-Francois |
title |
Degradation state of organic matter in surface sediments from the Southern Beaufort Sea: a lipid approach |
title_short |
Degradation state of organic matter in surface sediments from the Southern Beaufort Sea: a lipid approach |
title_full |
Degradation state of organic matter in surface sediments from the Southern Beaufort Sea: a lipid approach |
title_fullStr |
Degradation state of organic matter in surface sediments from the Southern Beaufort Sea: a lipid approach |
title_full_unstemmed |
Degradation state of organic matter in surface sediments from the Southern Beaufort Sea: a lipid approach |
title_sort |
degradation state of organic matter in surface sediments from the southern beaufort sea: a lipid approach |
publisher |
HAL CCSD |
publishDate |
2012 |
url |
https://hal.science/hal-00730371 https://hal.science/hal-00730371/document https://hal.science/hal-00730371/file/bg-9-3513-2012.pdf https://doi.org/10.5194/bg-9-3513-2012 |
genre |
Arctic Beaufort Sea Mackenzie Basin permafrost |
genre_facet |
Arctic Beaufort Sea Mackenzie Basin permafrost |
op_source |
ISSN: 1726-4170 EISSN: 1726-4189 Biogeosciences https://hal.science/hal-00730371 Biogeosciences, 2012, 9, pp.3513-3530. ⟨10.5194/bg-9-3513-2012⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-9-3513-2012 hal-00730371 https://hal.science/hal-00730371 https://hal.science/hal-00730371/document https://hal.science/hal-00730371/file/bg-9-3513-2012.pdf doi:10.5194/bg-9-3513-2012 |
op_rights |
http://creativecommons.org/licenses/by-nd/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/bg-9-3513-2012 |
container_title |
Biogeosciences |
container_volume |
9 |
container_issue |
9 |
container_start_page |
3513 |
op_container_end_page |
3530 |
_version_ |
1786824479855345664 |