Temperature induced decoupling of enzymatic hydrolysis and carbon remineralization in long-term incubations of Arctic and temperate sediments
Udgivelsesdato: 2010 Extracellular enzymatic hydrolysis of high-molecular weight organic matter is the initial step in sedimentary organic carbon degradation and is often regarded as the rate-limiting step. Temperature effects on enzyme activities may therefore exert an indirect control on carbon mi...
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ftuniaarhuspubl:oai:pure.atira.dk:publications/c1327860-ab83-11df-8c1a-000ea68e967b 2023-05-15T14:24:21+02:00 Temperature induced decoupling of enzymatic hydrolysis and carbon remineralization in long-term incubations of Arctic and temperate sediments Robador, Alberto Brüchert, Volker Steen, Andrew Arnosti, Carol 2010 application/pdf https://pure.au.dk/portal/da/publications/temperature-induced-decoupling-of-enzymatic-hydrolysis-and-carbon-remineralization-in-longterm-incubations-of-arctic-and-temperate-sediments(c1327860-ab83-11df-8c1a-000ea68e967b).html https://pure.au.dk/ws/files/36186920/Robador_et_al_2010_TGB_and_EEa.pdf eng eng info:eu-repo/semantics/openAccess Robador , A , Brüchert , V , Steen , A & Arnosti , C 2010 , ' Temperature induced decoupling of enzymatic hydrolysis and carbon remineralization in long-term incubations of Arctic and temperate sediments ' , Geochimica et Cosmochimica Acta , vol. 74 , no. 8 , pp. 2316-2326 . article 2010 ftuniaarhuspubl 2022-08-10T22:52:00Z Udgivelsesdato: 2010 Extracellular enzymatic hydrolysis of high-molecular weight organic matter is the initial step in sedimentary organic carbon degradation and is often regarded as the rate-limiting step. Temperature effects on enzyme activities may therefore exert an indirect control on carbon mineralization. We explored the temperature sensitivity of enzymatic hydrolysis and its connection to subsequent steps in anoxic organic carbon degradation in long-term incubations of sediments from the Arctic and the North Sea. These sediments were incubated under anaerobic conditions for 24 months at temperatures of 0, 10, and 20 ºC. The short-term temperature response of the active microbial community was tested in temperature gradient block incubations. The temperature optimum of extracellular enzymatic hydrolysis, as measured with a polysaccharide (chondroitin sulfate), differed between Arctic and temperate habitats by about 8–13 C in fresh sediments and in sediments incubated for 24 months. In both Arctic and temperate sediments, the temperature response of chondroitin sulfate hydrolysis was initially similar to that of sulfate reduction. After 24 months, however, hydrolysis outpaced sulfate reduction rates, as demonstrated by increased concentrations of dissolved organic carbon (DOC) and total dissolved carbohydrates. This effect was stronger at higher incubation temperatures, particularly in the Arctic sediments. In all experiments, concentrations of volatile fatty acids (VFA) were low, indicating tight coupling between VFA production and consumption. Together, these data indicate that long-term incubation at elevated temperatures led to increased decoupling of hydrolytic DOC production relative to fermentation. Temperature increases in marine sedimentary environments may thus significantly affect the downstream carbon mineralization and lead to the increased formation of refractory DOC. Article in Journal/Newspaper Arctic Arctic Aarhus University: Research Arctic |
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Aarhus University: Research |
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ftuniaarhuspubl |
language |
English |
description |
Udgivelsesdato: 2010 Extracellular enzymatic hydrolysis of high-molecular weight organic matter is the initial step in sedimentary organic carbon degradation and is often regarded as the rate-limiting step. Temperature effects on enzyme activities may therefore exert an indirect control on carbon mineralization. We explored the temperature sensitivity of enzymatic hydrolysis and its connection to subsequent steps in anoxic organic carbon degradation in long-term incubations of sediments from the Arctic and the North Sea. These sediments were incubated under anaerobic conditions for 24 months at temperatures of 0, 10, and 20 ºC. The short-term temperature response of the active microbial community was tested in temperature gradient block incubations. The temperature optimum of extracellular enzymatic hydrolysis, as measured with a polysaccharide (chondroitin sulfate), differed between Arctic and temperate habitats by about 8–13 C in fresh sediments and in sediments incubated for 24 months. In both Arctic and temperate sediments, the temperature response of chondroitin sulfate hydrolysis was initially similar to that of sulfate reduction. After 24 months, however, hydrolysis outpaced sulfate reduction rates, as demonstrated by increased concentrations of dissolved organic carbon (DOC) and total dissolved carbohydrates. This effect was stronger at higher incubation temperatures, particularly in the Arctic sediments. In all experiments, concentrations of volatile fatty acids (VFA) were low, indicating tight coupling between VFA production and consumption. Together, these data indicate that long-term incubation at elevated temperatures led to increased decoupling of hydrolytic DOC production relative to fermentation. Temperature increases in marine sedimentary environments may thus significantly affect the downstream carbon mineralization and lead to the increased formation of refractory DOC. |
format |
Article in Journal/Newspaper |
author |
Robador, Alberto Brüchert, Volker Steen, Andrew Arnosti, Carol |
spellingShingle |
Robador, Alberto Brüchert, Volker Steen, Andrew Arnosti, Carol Temperature induced decoupling of enzymatic hydrolysis and carbon remineralization in long-term incubations of Arctic and temperate sediments |
author_facet |
Robador, Alberto Brüchert, Volker Steen, Andrew Arnosti, Carol |
author_sort |
Robador, Alberto |
title |
Temperature induced decoupling of enzymatic hydrolysis and carbon remineralization in long-term incubations of Arctic and temperate sediments |
title_short |
Temperature induced decoupling of enzymatic hydrolysis and carbon remineralization in long-term incubations of Arctic and temperate sediments |
title_full |
Temperature induced decoupling of enzymatic hydrolysis and carbon remineralization in long-term incubations of Arctic and temperate sediments |
title_fullStr |
Temperature induced decoupling of enzymatic hydrolysis and carbon remineralization in long-term incubations of Arctic and temperate sediments |
title_full_unstemmed |
Temperature induced decoupling of enzymatic hydrolysis and carbon remineralization in long-term incubations of Arctic and temperate sediments |
title_sort |
temperature induced decoupling of enzymatic hydrolysis and carbon remineralization in long-term incubations of arctic and temperate sediments |
publishDate |
2010 |
url |
https://pure.au.dk/portal/da/publications/temperature-induced-decoupling-of-enzymatic-hydrolysis-and-carbon-remineralization-in-longterm-incubations-of-arctic-and-temperate-sediments(c1327860-ab83-11df-8c1a-000ea68e967b).html https://pure.au.dk/ws/files/36186920/Robador_et_al_2010_TGB_and_EEa.pdf |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Arctic |
genre_facet |
Arctic Arctic |
op_source |
Robador , A , Brüchert , V , Steen , A & Arnosti , C 2010 , ' Temperature induced decoupling of enzymatic hydrolysis and carbon remineralization in long-term incubations of Arctic and temperate sediments ' , Geochimica et Cosmochimica Acta , vol. 74 , no. 8 , pp. 2316-2326 . |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766296786368987136 |