Actinobacterial Nitrate Reducers and Proteobacterial Denitrifiers Are Abundant in N2O-Metabolizing Palsa Peat
Palsa peats are characterized by elevated, circular frost heaves (peat soil on top of a permanently frozen ice lens) and are strong to moderate sources or even temporary sinks for the greenhouse gas nitrous oxide (N2O). Palsa peats are predicted to react sensitively to global warming. The acidic pal...
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2012
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ftunivhannover:oai:www.repo.uni-hannover.de:123456789/16052 2024-02-11T10:04:42+01:00 Actinobacterial Nitrate Reducers and Proteobacterial Denitrifiers Are Abundant in N2O-Metabolizing Palsa Peat Palmer, Katharina Horn, Marcus A. 2012 https://www.repo.uni-hannover.de/handle/123456789/16052 https://doi.org/10.15488/15926 eng eng Washington, DC [u.a.] : American Soc. for Microbiology DOI:https://doi.org/10.1128/AEM.00810-12 ISSN:0099-2240 ESSN:1098-5336 http://dx.doi.org/10.15488/15926 https://www.repo.uni-hannover.de/handle/123456789/16052 Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. frei zugänglich Applied and Environmental Microbiology 78 (2012) Nr. 16 Anoxic microcosms Betaproteobacteria Consumption potential Discontinuous permafrost Operational taxonomic units ddc:570 status-type:publishedVersion doc-type:Article doc-type:Text 2012 ftunivhannover https://doi.org/10.15488/1592610.1128/AEM.00810-12 2024-01-21T23:46:57Z Palsa peats are characterized by elevated, circular frost heaves (peat soil on top of a permanently frozen ice lens) and are strong to moderate sources or even temporary sinks for the greenhouse gas nitrous oxide (N2O). Palsa peats are predicted to react sensitively to global warming. The acidic palsa peat Skalluvaara (approximate pH 4.4) is located in the discontinuous permafrost zone in northwestern Finnish Lapland. In situ N2O fluxes were spatially variable, ranging from 0.01 to -0.02 μmol of N2O m-2 h-1. Fertilization with nitrate stimulated in situ N2O emissions and N2O production in anoxic microcosms without apparent delay. N2O was subsequently consumed in microcosms. Maximal reaction velocities (vmax) of nitrate-dependent denitrification approx-imated 3 and 1 nmol of N2O per h per gram (dry weight [gDW]) in soil from 0 to 20 cm and below 20 cm of depth, respectively. vmax values of nitrite-dependent denitrification were 2- to 5-fold higher than the vmax nitrate-dependent denitrification, and vmax of N2O consumption was 1- to 6-fold higher than that of nitrite-dependent denitrification, highlighting a high N2O consumption potential. Up to 12 species-level operational taxonomic units (OTUs) of narG, nirK and nirS, and nosZ were retrieved. Detected OTUs suggested the presence of diverse uncultured soil denitrifiers and dissimilatory nitrate reducers, hitherto undetected spe- cies, as well as Actino-, Alpha-, and Betaproteobacteria. Copy numbers of nirS always outnumbered those of nirK by 2 orders of magnitude. Copy numbers of nirS tended to be higher, while copy numbers of narG and nosZ tended to be lower in 0- to 20-cm soil than in soil below 20 cm. The collective data suggest that (i) the source and sink functions of palsa peat soils for N2O are associated with denitrification, (ii) actinobacterial nitrate reducers and nirS-type and nosZ-harboring proteobacterial denitrifiers are important players, and (iii) acidic soils like palsa peats represent reservoirs of diverse acid-tolerant denitrifiers associated ... Article in Journal/Newspaper Ice palsa permafrost Lapland Institutional Repository of Leibniz Universität Hannover |
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Open Polar |
collection |
Institutional Repository of Leibniz Universität Hannover |
op_collection_id |
ftunivhannover |
language |
English |
topic |
Anoxic microcosms Betaproteobacteria Consumption potential Discontinuous permafrost Operational taxonomic units ddc:570 |
spellingShingle |
Anoxic microcosms Betaproteobacteria Consumption potential Discontinuous permafrost Operational taxonomic units ddc:570 Palmer, Katharina Horn, Marcus A. Actinobacterial Nitrate Reducers and Proteobacterial Denitrifiers Are Abundant in N2O-Metabolizing Palsa Peat |
topic_facet |
Anoxic microcosms Betaproteobacteria Consumption potential Discontinuous permafrost Operational taxonomic units ddc:570 |
description |
Palsa peats are characterized by elevated, circular frost heaves (peat soil on top of a permanently frozen ice lens) and are strong to moderate sources or even temporary sinks for the greenhouse gas nitrous oxide (N2O). Palsa peats are predicted to react sensitively to global warming. The acidic palsa peat Skalluvaara (approximate pH 4.4) is located in the discontinuous permafrost zone in northwestern Finnish Lapland. In situ N2O fluxes were spatially variable, ranging from 0.01 to -0.02 μmol of N2O m-2 h-1. Fertilization with nitrate stimulated in situ N2O emissions and N2O production in anoxic microcosms without apparent delay. N2O was subsequently consumed in microcosms. Maximal reaction velocities (vmax) of nitrate-dependent denitrification approx-imated 3 and 1 nmol of N2O per h per gram (dry weight [gDW]) in soil from 0 to 20 cm and below 20 cm of depth, respectively. vmax values of nitrite-dependent denitrification were 2- to 5-fold higher than the vmax nitrate-dependent denitrification, and vmax of N2O consumption was 1- to 6-fold higher than that of nitrite-dependent denitrification, highlighting a high N2O consumption potential. Up to 12 species-level operational taxonomic units (OTUs) of narG, nirK and nirS, and nosZ were retrieved. Detected OTUs suggested the presence of diverse uncultured soil denitrifiers and dissimilatory nitrate reducers, hitherto undetected spe- cies, as well as Actino-, Alpha-, and Betaproteobacteria. Copy numbers of nirS always outnumbered those of nirK by 2 orders of magnitude. Copy numbers of nirS tended to be higher, while copy numbers of narG and nosZ tended to be lower in 0- to 20-cm soil than in soil below 20 cm. The collective data suggest that (i) the source and sink functions of palsa peat soils for N2O are associated with denitrification, (ii) actinobacterial nitrate reducers and nirS-type and nosZ-harboring proteobacterial denitrifiers are important players, and (iii) acidic soils like palsa peats represent reservoirs of diverse acid-tolerant denitrifiers associated ... |
format |
Article in Journal/Newspaper |
author |
Palmer, Katharina Horn, Marcus A. |
author_facet |
Palmer, Katharina Horn, Marcus A. |
author_sort |
Palmer, Katharina |
title |
Actinobacterial Nitrate Reducers and Proteobacterial Denitrifiers Are Abundant in N2O-Metabolizing Palsa Peat |
title_short |
Actinobacterial Nitrate Reducers and Proteobacterial Denitrifiers Are Abundant in N2O-Metabolizing Palsa Peat |
title_full |
Actinobacterial Nitrate Reducers and Proteobacterial Denitrifiers Are Abundant in N2O-Metabolizing Palsa Peat |
title_fullStr |
Actinobacterial Nitrate Reducers and Proteobacterial Denitrifiers Are Abundant in N2O-Metabolizing Palsa Peat |
title_full_unstemmed |
Actinobacterial Nitrate Reducers and Proteobacterial Denitrifiers Are Abundant in N2O-Metabolizing Palsa Peat |
title_sort |
actinobacterial nitrate reducers and proteobacterial denitrifiers are abundant in n2o-metabolizing palsa peat |
publisher |
Washington, DC [u.a.] : American Soc. for Microbiology |
publishDate |
2012 |
url |
https://www.repo.uni-hannover.de/handle/123456789/16052 https://doi.org/10.15488/15926 |
genre |
Ice palsa permafrost Lapland |
genre_facet |
Ice palsa permafrost Lapland |
op_source |
Applied and Environmental Microbiology 78 (2012) Nr. 16 |
op_relation |
DOI:https://doi.org/10.1128/AEM.00810-12 ISSN:0099-2240 ESSN:1098-5336 http://dx.doi.org/10.15488/15926 https://www.repo.uni-hannover.de/handle/123456789/16052 |
op_rights |
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. frei zugänglich |
op_doi |
https://doi.org/10.15488/1592610.1128/AEM.00810-12 |
_version_ |
1790601428154187776 |