Aerobic release and biodegradation of dissolved organic matter from frozen peat : effects of temperature and heterotrophic bacteria
Understanding the conditions of dissolved organic matter (DOM) release from thawing peat in the Arctic regions and identifying the pathways of processing DOM by soil and aquatic heterotrophic bacteria are critical in the context of rapid climate change. Until now, experimental approaches did not all...
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ftird:oai:ird.fr:fdi:010077918 2023-05-15T15:18:09+02:00 Aerobic release and biodegradation of dissolved organic matter from frozen peat : effects of temperature and heterotrophic bacteria Payandi-Rolland, D. Shirokova, L. S. Nakhle, P. Tesfa, M. Abdou, A. Causserand, C. Lartiges, B. Rols, J. L. Guérin, Frédéric Benezeth, P. Pokrovsky, O. S. EUROPE RUSSIE 2020 http://www.documentation.ird.fr/hor/fdi:010077918 EN eng http://www.documentation.ird.fr/hor/fdi:010077918 oai:ird.fr:fdi:010077918 Payandi-Rolland D., Shirokova L. S., Nakhle P., Tesfa M., Abdou A., Causserand C., Lartiges B., Rols J. L., Guérin Frédéric, Benezeth P., Pokrovsky O. S. Aerobic release and biodegradation of dissolved organic matter from frozen peat : effects of temperature and heterotrophic bacteria. Chemical Geology, 2020, 536, p. art. 119448 [14 p.]. Organic carbon Permafrost Lixiviation TEM Microbial functional diversity text 2020 ftird 2020-08-21T06:48:09Z Understanding the conditions of dissolved organic matter (DOM) release from thawing peat in the Arctic regions and identifying the pathways of processing DOM by soil and aquatic heterotrophic bacteria are critical in the context of rapid climate change. Until now, experimental approaches did not allow quantitative predictions of temperature and biota effects on carbon release from peat in permafrost-affected aquatic environments. In this study, we incubated frozen peat and its aqueous leachate at various temperatures (4, 25 or 45 degrees C), with and without culturable heterotrophic bacteria Iodobacter sp., extracted from thermokarst lakes, to quantify the release and the removal rate of organic carbon (OC) with time. The metabolic diversity of the native microbial community associated with the substrates involved in OC processing was also characterized. Transmission electron microscopy revealed that, after degradation, the associated bacteria are mostly located in the inner parts of plant cells, and that the degradation of organic matter around bacteria is more pronounced at 4 and 25 degrees C compared to 45 degrees C. The metabolic diversity of heterotrophic bacteria was equally high at 4 and 25 degrees C, but lower at 45 degrees C. Regardless of the microbial consortium (native community alone or with added culturable heterotrophs), both the OC release from peat and the OC removal from peat leachate by bacteria were similar at 4 and 25 degrees C. Very low apparent activation energies of DOM biodegradation between 4 and 25 degrees C (- 4.23 +/- 12.3 kJ mol(-1)) suggest that the short-period of surface water warming in summer would have an insignificant effect on DOM microbial processing. Such duration (1-3 weeks) is comparable with the water residence time in peat depressions and permafrost subsidences, where peat degradation and DOM microbial processing occur. This questions the current paradigm of a drastic effect of temperature rise on organic carbon release from frozen peatlands, and should be considered for modelling short-term climate impacts in these regions. Text Arctic Climate change permafrost Thermokarst IRD (Institute de recherche pour le développement): Horizon Arctic |
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Open Polar |
collection |
IRD (Institute de recherche pour le développement): Horizon |
op_collection_id |
ftird |
language |
English |
topic |
Organic carbon Permafrost Lixiviation TEM Microbial functional diversity |
spellingShingle |
Organic carbon Permafrost Lixiviation TEM Microbial functional diversity Payandi-Rolland, D. Shirokova, L. S. Nakhle, P. Tesfa, M. Abdou, A. Causserand, C. Lartiges, B. Rols, J. L. Guérin, Frédéric Benezeth, P. Pokrovsky, O. S. Aerobic release and biodegradation of dissolved organic matter from frozen peat : effects of temperature and heterotrophic bacteria |
topic_facet |
Organic carbon Permafrost Lixiviation TEM Microbial functional diversity |
description |
Understanding the conditions of dissolved organic matter (DOM) release from thawing peat in the Arctic regions and identifying the pathways of processing DOM by soil and aquatic heterotrophic bacteria are critical in the context of rapid climate change. Until now, experimental approaches did not allow quantitative predictions of temperature and biota effects on carbon release from peat in permafrost-affected aquatic environments. In this study, we incubated frozen peat and its aqueous leachate at various temperatures (4, 25 or 45 degrees C), with and without culturable heterotrophic bacteria Iodobacter sp., extracted from thermokarst lakes, to quantify the release and the removal rate of organic carbon (OC) with time. The metabolic diversity of the native microbial community associated with the substrates involved in OC processing was also characterized. Transmission electron microscopy revealed that, after degradation, the associated bacteria are mostly located in the inner parts of plant cells, and that the degradation of organic matter around bacteria is more pronounced at 4 and 25 degrees C compared to 45 degrees C. The metabolic diversity of heterotrophic bacteria was equally high at 4 and 25 degrees C, but lower at 45 degrees C. Regardless of the microbial consortium (native community alone or with added culturable heterotrophs), both the OC release from peat and the OC removal from peat leachate by bacteria were similar at 4 and 25 degrees C. Very low apparent activation energies of DOM biodegradation between 4 and 25 degrees C (- 4.23 +/- 12.3 kJ mol(-1)) suggest that the short-period of surface water warming in summer would have an insignificant effect on DOM microbial processing. Such duration (1-3 weeks) is comparable with the water residence time in peat depressions and permafrost subsidences, where peat degradation and DOM microbial processing occur. This questions the current paradigm of a drastic effect of temperature rise on organic carbon release from frozen peatlands, and should be considered for modelling short-term climate impacts in these regions. |
format |
Text |
author |
Payandi-Rolland, D. Shirokova, L. S. Nakhle, P. Tesfa, M. Abdou, A. Causserand, C. Lartiges, B. Rols, J. L. Guérin, Frédéric Benezeth, P. Pokrovsky, O. S. |
author_facet |
Payandi-Rolland, D. Shirokova, L. S. Nakhle, P. Tesfa, M. Abdou, A. Causserand, C. Lartiges, B. Rols, J. L. Guérin, Frédéric Benezeth, P. Pokrovsky, O. S. |
author_sort |
Payandi-Rolland, D. |
title |
Aerobic release and biodegradation of dissolved organic matter from frozen peat : effects of temperature and heterotrophic bacteria |
title_short |
Aerobic release and biodegradation of dissolved organic matter from frozen peat : effects of temperature and heterotrophic bacteria |
title_full |
Aerobic release and biodegradation of dissolved organic matter from frozen peat : effects of temperature and heterotrophic bacteria |
title_fullStr |
Aerobic release and biodegradation of dissolved organic matter from frozen peat : effects of temperature and heterotrophic bacteria |
title_full_unstemmed |
Aerobic release and biodegradation of dissolved organic matter from frozen peat : effects of temperature and heterotrophic bacteria |
title_sort |
aerobic release and biodegradation of dissolved organic matter from frozen peat : effects of temperature and heterotrophic bacteria |
publishDate |
2020 |
url |
http://www.documentation.ird.fr/hor/fdi:010077918 |
op_coverage |
EUROPE RUSSIE |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Climate change permafrost Thermokarst |
genre_facet |
Arctic Climate change permafrost Thermokarst |
op_relation |
http://www.documentation.ird.fr/hor/fdi:010077918 oai:ird.fr:fdi:010077918 Payandi-Rolland D., Shirokova L. S., Nakhle P., Tesfa M., Abdou A., Causserand C., Lartiges B., Rols J. L., Guérin Frédéric, Benezeth P., Pokrovsky O. S. Aerobic release and biodegradation of dissolved organic matter from frozen peat : effects of temperature and heterotrophic bacteria. Chemical Geology, 2020, 536, p. art. 119448 [14 p.]. |
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1766348379211694080 |