DOI: 10.1073/pnas.1912313117
论文题名: Dark biological superoxide production as a significant flux and sink of marine dissolved oxygen
作者: Sutherland K.M. ; Wankel S.D. ; Hansel C.M.
刊名: Proceedings of the National Academy of Sciences of the United States of America
ISSN: 0027-8424
出版年: 2020
卷: 117, 期: 7 起始页码: 3433
结束页码: 3439
语种: 英语
英文关键词: Marine dissolved oxygen
; Microbial superoxide
; Reactive oxygen species
Scopus关键词: carbon
; dissolved oxygen
; oxygen
; reactive oxygen metabolite
; superoxide
; sea water
; superoxide
; Article
; biogeochemical cycling
; cell membrane
; controlled study
; electron
; marine bacterium
; marine environment
; nonhuman
; oxidation
; oxidation reduction state
; oxygen consumption
; oxygen transport
; photorespiration
; photosynthesis
; priority journal
; reduction (chemistry)
; source sink relationship
; chemistry
; oxidation reduction reaction
; sea
; Carbon
; Oceans and Seas
; Oxidation-Reduction
; Oxygen
; Reactive Oxygen Species
; Seawater
; Superoxides
英文摘要: The balance between sources and sinks of molecular oxygen in the oceans has greatly impacted the composition of Earth’s atmosphere since the evolution of oxygenic photosynthesis, thereby exerting key influence on Earth’s climate and the redox state of (sub)surface Earth. The canonical source and sink terms of the marine oxygen budget include photosynthesis, respiration, photorespiration, the Mehler reaction, and other smaller terms. However, recent advances in understanding cryptic oxygen cycling, namely the ubiquitous one-electron reduction of O2 to superoxide by microorganisms outside the cell, remains unexplored as a potential player in global oxygen dynamics. Here we show that dark extracellular superoxide production by marine microbes represents a previously unconsidered global oxygen flux and sink comparable in magnitude to other key terms. We estimate that extracellular superoxide production represents a gross oxygen sink comprising about a third of marine gross oxygen production, and a net oxygen sink amounting to 15 to 50% of that. We further demonstrate that this total marine dark extracellular superoxide flux is consistent with concentrations of superoxide in marine environments. These findings underscore prolific marine sources of reactive oxygen species and a complex and dynamic oxygen cycle in which oxygen consumption and corresponding carbon oxidation are not necessarily confined to cell membranes or exclusively related to respiration. This revised model of the marine oxygen cycle will ultimately allow for greater reconciliation among estimates of primary production and respiration and a greater mechanistic understanding of redox cycling in the ocean. © 2020 National Academy of Sciences. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164327
Appears in Collections: 气候变化与战略
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作者单位: Sutherland, K.M., Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States, Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Wankel, S.D., Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States; Hansel, C.M., Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
Recommended Citation:
Sutherland K.M.,Wankel S.D.,Hansel C.M.. Dark biological superoxide production as a significant flux and sink of marine dissolved oxygen[J]. Proceedings of the National Academy of Sciences of the United States of America,2020-01-01,117(7)