BioRxiv
bioRxiv Subject Collection: Systems Biology
This feed contains articles for bioRxiv Subject Collection "Systems Biology"
Oxygen intrusions sustain aerobic nitrite oxidation in anoxic marine zones
Anoxic marine zones (AMZs) are host to anaerobic metabolisms that drive losses of bioavailable nitrogen from the ocean. The discovery of active nitrite-oxidising bacteria (NOB), long thought to be obligately aerobic, in AMZs has altered our perception of how nitrogen cycles in these oxygen-deficient waters. Yet, why NOB succeed in AMZs remains unclear. Here, we show that obligately aerobic NOB can thrive alongside aerobic microheterotrophs in AMZs via infrequent intrusions of oxygen. Ecological theory, biogeochemical modelling and metagenome-based maximum growth rate estimates suggest that NOB are opportunists that take advantage of periodic oxygen intrusions to rapidly accumulate biomass. Rather than harsh, AMZs prone to oxygen intrusions appear optimal for NOB, whose abundance and activity peaks in a goldilocks zone of periodic oxygen and high nitrite supply. Our results recast the intermediate disturbance hypothesis to AMZs and highlight how the nitrogen cycle relies on dynamic coexistence of aerobic and anaerobic metabolisms.
Buchanan, P. J., Sun, X., Weissman, J., Zakem, E.
February 23, 2023
http://biorxiv.org/cgi/content/short/2023.02.22.529547v1?rss=1