Stable aerobic and anaerobic coexistence in anoxic marine zones
Name
s41396-019-0523-8.pdf
Description
Published version
Size
1.48 MB
Format
Adobe PDF
Checksum (MD5)
5535e7b87310599bebad182407535ff3
Author(s)
Zakem, Emily Juliette
Mahadevan, Amala
Lauderdale, Jonathan
Follows, Michael J
Date Issued
October 2019
Journal
The ISME Journal
Publisher
Springer Science and Business Media LLC
Citation
Zakem, Emily J. et al. “Stable aerobic and anaerobic coexistence in anoxic marine zones.” The ISME Journal 14 (2019): 288-301 © 2019 The Author(s)
Version
Final published version
Abstract
Mechanistic description of the transition from aerobic to anaerobic metabolism is necessary for diagnostic and predictive modeling of fixed nitrogen loss in anoxic marine zones (AMZs). In a metabolic model where diverse oxygen- and nitrogen-cycling microbial metabolisms are described by underlying redox chemical reactions, we predict a transition from strictly aerobic to predominantly anaerobic regimes as the outcome of ecological interactions along an oxygen gradient, obviating the need for prescribed critical oxygen concentrations. Competing aerobic and anaerobic metabolisms can coexist in anoxic conditions whether these metabolisms represent obligate or facultative populations. In the coexistence regime, relative rates of aerobic and anaerobic activity are determined by the ratio of oxygen to electron donor supply. The model simulates key characteristics of AMZs, such as the accumulation of nitrite and the sustainability of anammox at higher oxygen concentrations than denitrification, and articulates how microbial biomass concentrations relate to associated water column transformation rates as a function of redox stoichiometry and energetics. Incorporating the metabolic model into an idealized two-dimensional ocean circulation results in a simulated AMZ, in which a secondary chlorophyll maximum emerges from oxygen-limited grazing, and where vertical mixing and dispersal in the oxycline also contribute to metabolic co-occurrence. The modeling approach is mechanistic yet computationally economical and suitable for global change applications.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Woods Hole Oceanographic Institution
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1038/S41396-019-0523-8
