Related Experiment Video
Updated: Jul 16, 2026
10:11
The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations
Published on: August 3, 2016
Dissolved oxygen concentrations influence microbial community structure and key players in an oxygen minimum zone
Kaitlin R Dombroski1, Lauren G Campbell1, Robert M Morris2
1Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, Florida, USA.
Msphere
|July 15, 2026
Summary
Expanding oxygen minimum zones (OMZs) alter marine microbial communities. In the northern Benguela Upwelling System, declining oxygen increases Thioglobaceae abundance, which can enhance nitrous oxide (N₂O) production due to incomplete denitrification.
Area of Science:
- Marine microbial ecology and biogeochemistry
- Oceanography and climate change impacts
Background:
- Oxygen minimum zones (OMZs) are expanding globally, impacting marine microbial processes and biogeochemical cycles.
- Nitrous oxide (N₂O), a potent greenhouse gas, is produced by microbial pathways influenced by oxygen availability.
- The northern Benguela Upwelling System (nBUS) is an important OMZ and a significant source of marine N₂O, yet its microbial responses are poorly understood.
Purpose of the Study:
- To investigate the influence of oxygen concentrations on microbial community structure in the nBUS OMZ.
- To assess the metabolic potential of dominant microbial groups, particularly Thioglobaceae, for N₂O production.
- To link OMZ-driven microbial shifts to potential changes in N₂O cycling.
Main Methods:
- Analysis of 16S rRNA gene sequences to characterize microbial communities across varying oxygen levels in the nBUS OMZ.
- Comparative genomic analysis of 216 Thioglobaceae genomes from OMZs worldwide.
- Correlation analysis between oxygen concentrations, microbial diversity, community evenness, and Thioglobaceae abundance.
Main Results:
- Microbial diversity was highest under dysoxic conditions and lowest under suboxic conditions, primarily due to changes in community evenness.
- The relative abundance of Thioglobaceae (SUP05) increased significantly as oxygen concentrations declined.
- Genomic analysis revealed Thioglobaceae possess metabolic pathways for carbon fixation, sulfur oxidation, and denitrification, but often lack the gene for complete N₂O reduction to N₂.
Conclusions:
- Declining oxygen in the nBUS OMZ favors the proliferation of Thioglobaceae.
- The incomplete denitrification potential of abundant Thioglobaceae suggests a mechanism for enhanced N₂O production in expanding OMZs.
- This study connects oxygen-driven microbial community shifts to increased N₂O emissions from OMZs.
Keywords:
16S rRNABenguelaEBUEN2ONamibiaOMZSUP05Thioglobaceaealpha diversitydissolved oxygenincomplete denitrificationnBUSomicsMore Related Videos
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