Substantial oxygen consumption by aerobic nitrite oxidation in oceanic oxygen minimum zones
Journal
Nature Communications
Journal Volume
12
Journal Issue
1
Date Issued
2021
Author(s)
Beman J.M
Vargas S.M
Wilson J.M
Perez-Coronel E
Karolewski J.S
Vazquez S
Cairo A.E
White M.E
Koester I
Aluwihare L.I
Wankel S.D.
Abstract
Oceanic oxygen minimum zones (OMZs) are globally significant sites of biogeochemical cycling where microorganisms deplete dissolved oxygen (DO) to concentrations <20 µM. Amid intense competition for DO in these metabolically challenging environments, aerobic nitrite oxidation may consume significant amounts of DO and help maintain low DO concentrations, but this remains unquantified. Using parallel measurements of oxygen consumption rates and 15N-nitrite oxidation rates applied to both water column profiles and oxygen manipulation experiments, we show that the contribution of nitrite oxidation to overall DO consumption systematically increases as DO declines below 2 µM. Nitrite oxidation can account for all DO consumption only under DO concentrations <393 nM found in and below the secondary chlorophyll maximum. These patterns are consistent across sampling stations and experiments, reflecting coupling between nitrate reduction and nitrite-oxidizing Nitrospina with high oxygen affinity (based on isotopic and omic data). Collectively our results demonstrate that nitrite oxidation plays a pivotal role in the maintenance and biogeochemical dynamics of OMZs. © 2021, The Author(s).
Other Subjects
chlorophyll; dissolved oxygen; nitrate; nitrite; nitrogen 15; oxygen; RNA 16S; water; nitrite; nitrogen; oxygen; biogeochemical cycle; concentration (composition); nitrite; ocean; oxic conditions; oxidation; oxygen consumption; oxygen minimum layer; water column; Article; biogeochemical cycle; concentration (parameter); controlled study; cross coupling reaction; metagenomics; nitrite oxidizing bacterium; Nitrospina; nonhuman; oxidation; oxygen affinity; oxygen consumption; oxygen consumption rate; reduction (chemistry); sea; bacterium; chemistry; ecosystem; metabolism; microbiology; oxidation reduction reaction; sea; solubility; Nitrospina; Bacteria; Chlorophyll; Ecosystem; Nitrites; Nitrogen Isotopes; Oceans and Seas; Oxidation-Reduction; Oxygen; Solubility; Water Microbiology
Type
journal article