Abstract
Peat particulate organic matter (POM) is an important terminal electron acceptor for anaerobic respiration in northern peatlands provided that the electron-accepting capacity of POM is periodically restored by oxidation with O2 during peat oxygenation events. We employed push-pull tests with dissolved O2 as reactant to determine pseudo-first-order rate constants of O2 consumption ( kobs) in anoxic peat soil of an unperturbed Swedish ombrotrophic bog. Dissolved O2 was rapidly consumed in anoxic peat with a mean kobs of 2.91 ± 0.60 h-1, corresponding to an O2 half-life of ∼14 min. POM dominated O2 consumption, as evidenced from approximately 50-fold smaller kobs in POM-free control tests. Inhibiting microbial activity with formaldehyde did not appreciably slow O2 consumption, supporting abiotic O2 reduction by POM moieties, not aerobic respiration, as the primary route of O2 consumption. Peat preoxygenation with dissolved O2 lowered kobs in subsequent oxygen consumption tests, consistent with depletion of reduced moieties in POM. Finally, repeated oxygen consumption tests demonstrated that anoxic peat POM has a high reduction capacity, in excess to 20 μmol electrons donated per gram POM. This work demonstrates rapid abiotic oxida...Continue Reading
References
Mar 7, 2002·Environmental Science & Technology·James T Nurmi, Paul G Tratnyek
Mar 28, 2002·Applied and Environmental Microbiology·Jutta KleikemperJosef Zeyer
Aug 10, 2002·The Science of the Total Environment·O M Bragg
Dec 6, 2003·Proceedings of the National Academy of Sciences of the United States of America·Cornelis RappoldtCornelis J van Duijn
Jan 11, 2005·Applied and Environmental Microbiology·Jutta KleikemperJosef Zeyer
Sep 1, 1994·Applied and Environmental Microbiology·L TuominenH Hartikainen
Mar 25, 2006·Ground Water·Martin H Schroth, Jonathan D Istok
Aug 14, 2009·Environmental Science & Technology·Iris Bauer, Andreas Kappler
Sep 1, 2002·FEMS Microbiology Ecology·Silvina A PomboJosef Zeyer
Dec 3, 2009·Environmental Science & Technology·Michael AeschbacherRené P Schwarzenbach
Oct 12, 2010·Chemical Reviews·Jeffrey J WarrenJames M Mayer
Jun 30, 2011·Environmental Science & Technology·Kajsa KnechtBernd Nowack
Aug 10, 2011·Environmental Science & Technology·Michael AeschbacherMichael Sander
May 16, 2012·Environmental Science & Technology·Chunfang Zhang, Arata Katayama
Mar 19, 2013·Global Change Biology·Scott D BridghamQianlai Zhuang
Nov 14, 2013·Applied Microbiology and Biotechnology·Claudia M MartinezFrancisco J Cervantes
Jul 1, 2015·Nature Communications·K E A SegarraS B Joye
Oct 22, 2015·Environmental Science & Technology·Brady A ZieglerIsabelle M Cozzarelli
Feb 26, 2016·Science·Silvan SchellerVictoria J Orphan
May 1, 1991·Ecological Applications : a Publication of the Ecological Society of America·Eville Gorham
Mar 28, 2017·Applied and Environmental Microbiology·Edgardo I ValenzuelaFrancisco J Cervantes
Apr 11, 2018·Environmental Science & Technology·Nicolas WalpenMichael Sander