Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1128/aem.72.2.1013-1018.2006
Title (Primary) In vivo emission of dinitrogen by earthworms via denitrifying bacteria in the gut
Author Horn, M.A.; Mertel, R.; Gehre, M.; Kästner, M.; Drake, H.L.
Source Titel Applied and Environmental Microbiology
Year 2006
Department ISOBIO; UBT
Volume 72
Issue 2
Page From 1013
Page To 1018
Language englisch
Abstract Earthworms emit the greenhouse gas nitrous oxide (N2O), and ingested denitrifiers in the gut appear to be the main source of this N2O. The primary goal of this study was to determine if earthworms also emit dinitrogen (N2), the end product of complete denitrification. When [15N]nitrate was injected into the gut, the earthworms Aporrectodea caliginosa and Lumbricus terrestris emitted labeled N2 (and also labeled N2O) under in vivo conditions; emission of N2 by these two earthworms was relatively linear and approximated 1.2 and 6.6 nmol N2 per h per g (fresh weight), respectively. Isolated gut contents also produced [15N]nitrate-derived N2 and N2O under anoxic conditions. N2 is formed by N2O reductase, and acetylene, an inhibitor of this enzyme, inhibited the emission of [15N]nitrate-derived N2 by living earthworms. Standard gas chromatographic analysis demonstrated that the amount of N2O emitted was relatively linear during initial incubation periods and increased in response to acetylene. The calculated rates for the native emissions of N2 (i.e., without added nitrate) by A. caliginosa and L. terrestris were 1.1 and 1.5 nmol N2 per h per g (fresh weight), respectively; these emission rates approximated that of N2O. These collective observations indicate that (i) earthworms emit N2 concomitant with the emission of N2O via the in situ activity of denitrifying bacteria in the gut and (ii) N2O is quantitatively an important denitrification-derived end product under in situ conditions.
Persistent UFZ Identifier
Horn, M.A., Mertel, R., Gehre, M., Kästner, M., Drake, H.L. (2006):
In vivo emission of dinitrogen by earthworms via denitrifying bacteria in the gut
Appl. Environ. Microb. 72 (2), 1013 - 1018 10.1128/aem.72.2.1013-1018.2006