Publication Date:
2013-05-04
Description:
Superoxide and other reactive oxygen species (ROS) originate from several natural sources and profoundly influence numerous elemental cycles, including carbon and trace metals. In the deep ocean, the permanent absence of light precludes currently known ROS sources, yet ROS production mysteriously occurs. Here, we show that taxonomically and ecologically diverse heterotrophic bacteria from aquatic and terrestrial environments are a vast, unrecognized, and light-independent source of superoxide, and perhaps other ROS derived from superoxide. Superoxide production by a model bacterium within the ubiquitous Roseobacter clade involves an extracellular oxidoreductase that is stimulated by the reduced form of nicotinamide adenine dinucleotide (NADH), suggesting a surprising homology with eukaryotic organisms. The consequences of ROS cycling in immense aphotic zones representing key sites of nutrient regeneration and carbon export must now be considered, including potential control of carbon remineralization and metal bioavailability.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Diaz, Julia M -- Hansel, Colleen M -- Voelker, Bettina M -- Mendes, Chantal M -- Andeer, Peter F -- Zhang, Tong -- New York, N.Y. -- Science. 2013 Jun 7;340(6137):1223-6. doi: 10.1126/science.1237331. Epub 2013 May 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23641059" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Carbon Cycle
;
*Heterotrophic Processes
;
Mercury/*metabolism
;
Molecular Sequence Data
;
NAD/metabolism
;
Oxidoreductases/metabolism
;
Phylogeny
;
Roseobacter/classification/*metabolism
;
Superoxides/*metabolism
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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