气候变化领域集成服务门户(CCPortal): Dark biological superoxide production as a significant flux and sink of marine dissolved oxygen

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DOI	10.1073/pnas.1912313117
	Dark biological superoxide production as a significant flux and sink of marine dissolved oxygen
	Sutherland K.M.; Wankel S.D.; Hansel C.M.
发表日期	2020
ISSN	0027-8424
起始页码	3433
结束页码	3439
卷号	117 期号:7
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.
英文关键词	Marine dissolved oxygen; Microbial superoxide; Reactive oxygen species
语种	英语
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
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/161058
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
推荐引用方式 GB/T 7714	Sutherland K.M.,Wankel S.D.,Hansel C.M.. Dark biological superoxide production as a significant flux and sink of marine dissolved oxygen[J],2020,117(7).
APA	Sutherland K.M.,Wankel S.D.,&Hansel C.M..(2020).Dark biological superoxide production as a significant flux and sink of marine dissolved oxygen.Proceedings of the National Academy of Sciences of the United States of America,117(7).
MLA	Sutherland K.M.,et al."Dark biological superoxide production as a significant flux and sink of marine dissolved oxygen".Proceedings of the National Academy of Sciences of the United States of America 117.7(2020).