Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

Megumi Kuroiwa; Keitaro Fukushima; Kazuma Hashimoto; Yukiko Senga; Tsubasa Sato; Chie Katsuyama; Yuichi Suwa

doi:10.3791/59562

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 1...

JoVE Journal
Environment

A subscription to JoVE is required to view this content. Sign in or start your free trial.

JoVE Journal Environment

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on ¹⁴NH₄⁺/¹⁵NH₄⁺ Analyses via Sequential Conversion to N₂O

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

Full Text

6,632 Views

08:05 min

October 7, 2020

DOI: 10.3791/59562-v

Megumi Kuroiwa¹, Keitaro Fukushima^2,3, Kazuma Hashimoto², Yukiko Senga⁴, Tsubasa Sato⁴, Chie Katsuyama⁵, Yuichi Suwa¹

¹Department of Biological Sciences, Faculty of Science and Engineering,Chuo University, ²Faculty & Graduate School of Urban Environmental Sciences,Tokyo Metropolitan University, ³Center for Ecological Research,Kyoto University, ⁴Department of Chemistry, Faculty of Science,Toho University, ⁵Graduate School of Integrated Arts and Sciences,Hiroshima University

A series of methods to determine the potential DNRA rate based on ¹⁴NH₄⁺/¹⁵NH₄⁺ analyses is provided in detail. NH₄⁺ is converted into N₂O via several steps and analyzed using quadrupole gas chromatography–mass spectrometry.

Coastal and the marine ecosystems are important as reservoirs, for removing nitrate from terrestrial ecosystems. Nitrate in aquatic environment can be consumed by several processes simultaneously. Such as denitrification, anammox and DNRA.

While previous studies have shown that DNRA is potentially culpable to denitrification, studies measuring DNRA activity as still very limited compared to those measuring denitrification. In our protocol, we provide a detailed procedure for the measurement of the potential DNRA rate in environmental samples. We believe that potential DNRA rate can be calculated from N15 labeled Ammonium accumulation with N15 labeled Nitrate addition.

View the full transcript and gain access to thousands of scientific videos