Reactivity of inorganic mn and mn desferrioxamine b with o2, o2–, and h2o2in seawater
Wuttig, Kathrin Heller, Maija I. Croot, Peter L.
Wuttig, Kathrin
Heller, Maija I.
Croot, Peter L.
Identifiers
http://hdl.handle.net/10379/14458
https://doi.org/10.13025/26626
https://doi.org/10.13025/26626
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Publication Date
2013-08-22
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Article
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Wuttig, Kathrin; Heller, Maija I. Croot, Peter L. (2013). Reactivity of inorganic mn and mn desferrioxamine b with o2, o2–, and h2o2in seawater. Environmental Science & Technology 47 (18), 10257-10265
Abstract
Manganese (Mn) is a required element for oceanic phytoplankton as it plays a critical role in photosynthesis, through its unique redox chemistry, as the active site in photosystem II, and in enzymes that act as defenses against reactive oxygen species (ROS), most notably for protection against superoxide (O-2(-)), through the action of superoxide dismutase (SOD), and against hydrogen peroxide (H2O2) via peroxidases and catalases. The distribution and redox speciation of Mn in the ocean is also apparently controlled by reactions with ROS. Here we examine the connections between ROS and dissolved Mn species in the upper ocean using field and laboratory experimental data. Our results suggest it is unlikely that significant concentrations of Mn(III) are produced in the euphotic zone, as in the absence of evidence for the existence of strong Mn(III) ligands, Mn(II) reacts with O-2(-) to form the short-lived transient manganous superoxide, MnO2+, which may react rapidly with other redox species in a manner similar to O-2(-). Experiments with the strong Mn(III) chelator, desferrioxamine B (DFB), in seawater indicated that the Mn(III) species are unlikely to form, as formation of the precursor Mn(II) complex is hindered due to the stability of the Ca complex with DFB.
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Publisher
American Chemical Society (ACS)
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Attribution-NonCommercial-NoDerivs 3.0 Ireland