Nitrogen isotope effects induced by anammox bacteria

Brunner, B; Contreras, S; Lehmann, MF; Matantseva, O; Rollog, M; Kalvelage, T; Klockgether, G; Lavik, G; Jetten, MS; Kartal, B; Kuypers, MM

HERO ID

2232984

Reference Type

Journal Article

Year

2013

Language

English

PMID

24191043

HERO ID 2232984
In Press No
Year 2013
Title Nitrogen isotope effects induced by anammox bacteria
Authors Brunner, B; Contreras, S; Lehmann, MF; Matantseva, O; Rollog, M; Kalvelage, T; Klockgether, G; Lavik, G; Jetten, MS; Kartal, B; Kuypers, MM
Journal Proceedings of the National Academy of Sciences of the United States of America
Volume 110
Issue 47
Page Numbers 18994-18999
Abstract Nitrogen (N) isotope ratios ((15)N/(14)N) provide integrative constraints on the N inventory of the modern ocean. Anaerobic ammonium oxidation (anammox), which converts ammonium and nitrite to dinitrogen gas (N2) and nitrate, is an important fixed N sink in marine ecosystems. We studied the so far unknown N isotope effects of anammox in batch culture experiments. Anammox preferentially removes (14)N from the ammonium pool with an isotope effect of +23.5‰ to +29.1‰, depending on factors controlling reversibility. The N isotope effects during the conversion of nitrite to N2 and nitrate are (i) inverse kinetic N isotope fractionation associated with the oxidation of nitrite to nitrate (-31.1 ± 3.9‰), (ii) normal kinetic N isotope fractionation during the reduction of nitrite to N2 (+16.0 ± 4.5‰), and (iii) an equilibrium N isotope effect between nitrate and nitrite (-60.5 ± 1.0‰), induced when anammox is exposed to environmental stress, leading to the superposition of N isotope exchange effects upon kinetic N isotope fractionation. Our findings indicate that anammox may be responsible for the unresolved large N isotope offsets between nitrate and nitrite in oceanic oxygen minimum zones. Irrespective of the extent of N isotope exchange between nitrate and nitrite, N removed from the combined nitrite and nitrate (NOx) pool is depleted in (15)N relative to NOx. This net N isotope effect by anammox is superimposed on the N isotope fractionation by the co-occurring reduction of nitrate to nitrite in suboxic waters, possibly enhancing the overall N isotope effect for N loss from oxygen minimum zones.
Doi 10.1073/pnas.1310488110
Pmid 24191043
Wosid WOS:000327100600068
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English