Related Experiment Video
Updated: Aug 6, 2026

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors
Published on: December 6, 2018
Substantial N2O Accumulation under Acidic Oxic Conditions Driven by Constrained N2O Reduction in a Denitrifying
Zicheng Su1, Tao Liu2, Jing Zhao3
1Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St. Lucia, Queensland 4072, Australia.
This study shows how acidic, oxygen-rich conditions cause significant nitrous oxide (N2O) buildup in denitrifying cultures. Microbial community functions, particularly constrained N2O reduction, drive these greenhouse gas emissions.
Area of Science:
- Microbiology
- Environmental Science
- Biogeochemistry
Background:
- Nitrous oxide (N2O) is a potent greenhouse gas.
- N2O is an intermediate in microbial nitrogen cycling.
- N2O rarely dominates total nitrogen fluxes.
Purpose of the Study:
- Investigate N2O accumulation in enriched denitrifying cultures.
- Analyze microbial community structure and function under specific conditions.
- Determine factors driving N2O emissions.
Main Methods:
- Utilized enriched denitrifying cultures with nitrite and acetate.
- Maintained cultures under acidic (pH 4.8-5.0) and oxic (>7 mg O2/L) conditions.
- Employed metagenomic and metatranscriptomic analyses.
Main Results:
- Observed substantial N2O accumulation (60-70% of total nitrogen flux).
- Identified distinct roles for Ottowia (N2O accumulation) and Rhodanobacteraceae (N2O production/reduction).
- Found Mycobacterium specialized in NO detoxification, with constrained N2O reduction under tested conditions.
Conclusions:
- N2O accumulation results from incomplete denitrification under acidic, oxic conditions.
- Low pH, oxygen, and nitrite inhibit N2O reductase activity.
- Constrained N2O reduction and functional partitioning drive emissions in engineered systems.
More Related Videos
09:38Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures
Published on: January 7, 2019
08:05Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
Published on: October 7, 2020
Related Concept Videos
Inorganic Nitrogen Assimilation
Microbes and the Nitrogen Cycle
Metabolism of Chemolithotrophs
2° Amines to N-Nitrosamines: Reaction with NaNO2
Microbial Mats
Carbon-dioxide Fixation