Aquatic respiration rate measurements at low oxygen concentrations

Moritz Holtappels; Laura Tiano; Tim Kalvelage; Gaute Lavik; Niels Peter Revsbech; Marcel M M Kuypers

doi:10.1371/journal.pone.0089369

Aquatic respiration rate measurements at low oxygen concentrations

PLoS One. 2014 Feb 19;9(2):e89369. doi: 10.1371/journal.pone.0089369. eCollection 2014.

Authors

Moritz Holtappels¹, Laura Tiano², Tim Kalvelage³, Gaute Lavik¹, Niels Peter Revsbech², Marcel M M Kuypers¹

Affiliations

¹ Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany.
² Department of Bioscience, Microbiology, Aarhus University, Aarhus, Denmark.
³ Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany ; Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada.

Abstract

Despite its huge ecological importance, microbial oxygen respiration in pelagic waters is little studied, primarily due to methodological difficulties. Respiration measurements are challenging because of the required high resolution of oxygen concentration measurements. Recent improvements in oxygen sensing techniques bear great potential to overcome these limitations. Here we compare 3 different methods to measure oxygen consumption rates at low oxygen concentrations, utilizing amperometric Clark type sensors (STOX), optical sensors (optodes), and mass spectrometry in combination with (18-18)O2 labeling. Oxygen concentrations and consumption rates agreed well between the different methods when applied in the same experimental setting. Oxygen consumption rates between 30 and 400 nmol L(-1) h(-1) were measured with high precision and relative standard errors of less than 3%. Rate detection limits in the range of 1 nmol L(-1) h(-1) were suitable for rate determinations in open ocean water and were lowest at the lowest applied O2 concentration.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Electrochemistry / instrumentation
Electrochemistry / methods*
Kinetics
Mass Spectrometry
Oceans and Seas
Oxygen Consumption / physiology*
Oxygen Isotopes / metabolism*
Seawater / chemistry*

Substances

Oxygen Isotopes

Grants and funding

The study was funded by the Max-Planck-Gesellschaft (www.mpg.de), the DFG-Research Center/Cluster of Excellence “The Ocean in the Earth System” at the University of Bremen (http://www.marum.de), the DFG-funded Sonderforschungsbereich 754 "Climate-Biogeochemistry Interactions in the Tropical Ocean" (www.sfb754.de), the European Union project “HYPOX - In situ monitoring of oxygen depletion in hypoxic ecosystems of coastal and open seas and land-locked water bodies”, EC grant 226213 (http://ec.europa.eu/research/fp7), the European Research Council, grant 267233 (www.erc.europa.eu), and the Danish Council for Independent Research: Natural Sciences, grant 10-083140 (http://en.fi.dk/councils-commissions/the-danishcouncil-for-independent-research). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.