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<DIV id=cite><FONT size=3><I>Nature</I> </FONT><B>457</B>, 581-584</DIV>
<DIV>29 January 2009</DIV>
<DIV><SPAN class=doi><ABBR
title="Digital Object Identifier">doi</ABBR>:10.1038/nature07588</SPAN></DIV>
<DIV>
<P id=errorcor></P>
<H2 id=atl><FONT size=4>Detoxification of sulphidic African shelf waters by
blooming chemolithotrophs</FONT></H2>
<P id=aug>Gaute Lavik<SUP><A title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a1">1</A>,</SUP><SUP><A
title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a5">5</A></SUP>,
Torben Stührmann<SUP><A title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a1">1</A>,</SUP><SUP><A
title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a5">5</A></SUP>,
Volker Brüchert<SUP><A title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a1">1</A>,</SUP><SUP><A
title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a6">6</A></SUP>,
Anja Van der Plas<SUP><A title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a2">2</A></SUP>,
Volker Mohrholz<SUP><A title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a3">3</A></SUP>,
Phyllis Lam<SUP><A title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a1">1</A></SUP>,
Marc Mu<IMG
style="BORDER-TOP-WIDTH: 0px; BORDER-LEFT-WIDTH: 0px; BORDER-BOTTOM-WIDTH: 0px; VERTICAL-ALIGN: middle; BORDER-RIGHT-WIDTH: 0px"
alt="s zlig"
src="http://www.nature.com/__chars/s/special/zlig/black/med/base/glyph.gif">mann<SUP><A
title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a4">4</A></SUP>,
Bernhard M. Fuchs<SUP><A title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a1">1</A></SUP>,
Rudolf Amann<SUP><A title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a1">1</A></SUP>,
Ulrich Lass<SUP><A title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a3">3</A></SUP>
& Marcel M. M. Kuypers<SUP><A title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a1">1</A></SUP></P>
<DIV id=affiliations-notes>
<OL class=decimal>
<LI id=a1>Max Planck Institute for Marine Microbiology, Celsiusstrasse 1,
D-28359 Bremen, Germany
<LI id=a2>National Marine Information & Research Centre Ministry of
Fisheries & Marine Resources, PO Box 912, Swakopmund, Namibia
<LI id=a3>Baltic Sea Research Institute Warnemünde, Seestrasse 15, D-18119
Rostock, Germany
<LI id=a4>Department of Microbial Ecology, Vienna Ecology Centre, University
of Vienna, Althanstra<IMG
style="BORDER-TOP-WIDTH: 0px; BORDER-LEFT-WIDTH: 0px; BORDER-BOTTOM-WIDTH: 0px; VERTICAL-ALIGN: middle; BORDER-RIGHT-WIDTH: 0px"
alt="s zlig"
src="http://www.nature.com/__chars/s/special/zlig/black/med/base/glyph.gif">e
14, A-1090 Vienna, Austria
<LI id=a5>These authors contributed equally to this work.
<LI id=a6>Present address: Department of Geology and Geochemistry, Stockholm
University, Svante Arrhenius väg 8C, 106 91 Stockholm, Sweden.</LI></OL>
<P class=caff>Correspondence to: Marcel M. M. Kuypers<SUP><A
title="affiliated with "
href="http://www.nature.com/nature/journal/v457/n7229/abs/nature07588.html?lang=en#a1">1</A></SUP> <A
href="mailto:mkuypers@mpi-bremen.de">mkuypers@mpi-bremen.de</A></P>
<P class=caff></P></DIV>
<DIV id=abs>
<P class=lead>Coastal waters support <IMG
style="BORDER-TOP-WIDTH: 0px; BORDER-LEFT-WIDTH: 0px; BORDER-BOTTOM-WIDTH: 0px; VERTICAL-ALIGN: baseline; BORDER-RIGHT-WIDTH: 0px"
alt=approx
src="http://www.nature.com/__chars/math/special/sim/black/med/base/glyph.gif">90
per cent of global fisheries and are therefore an important food reserve for our
planet<SUP><A
href="http://www.nature.com/nature/journal/v457/n7229/full/nature07588.html#B1">1</A></SUP>.
Eutrophication of these waters, due to human activity, leads to severe oxygen
depletion and the episodic occurrence of hydrogen sulphide—toxic to
multi-cellular life—with disastrous consequences for coastal ecosytems<SUP><A
href="http://www.nature.com/nature/journal/v457/n7229/full/nature07588.html#B2">2,
</A></SUP><SUP><A
href="http://www.nature.com/nature/journal/v457/n7229/full/nature07588.html#B3">3,
</A></SUP><SUP><A
href="http://www.nature.com/nature/journal/v457/n7229/full/nature07588.html#B4">4,
</A></SUP><SUP><A
href="http://www.nature.com/nature/journal/v457/n7229/full/nature07588.html#B5">5</A></SUP>.
Here we show that an area of <IMG
style="BORDER-TOP-WIDTH: 0px; BORDER-LEFT-WIDTH: 0px; BORDER-BOTTOM-WIDTH: 0px; VERTICAL-ALIGN: baseline; BORDER-RIGHT-WIDTH: 0px"
alt=approx
src="http://www.nature.com/__chars/math/special/sim/black/med/base/glyph.gif">7,000 km<SUP>2</SUP>
of African shelf, covered by sulphidic water, was detoxified by blooming
bacteria that oxidized the biologically harmful sulphide to environmentally
harmless colloidal sulphur and sulphate. </P>
<P class=lead>Combined chemical analyses, stoichiometric modelling, isotopic
incubations, comparative 16S ribosomal RNA, functional gene sequence analyses
and fluorescence <I>in situ</I> hybridization indicate that the detoxification
proceeded by chemolithotrophic oxidation of sulphide with nitrate and was mainly
catalysed by two discrete populations of <IMG
style="BORDER-TOP-WIDTH: 0px; BORDER-LEFT-WIDTH: 0px; BORDER-BOTTOM-WIDTH: 0px; VERTICAL-ALIGN: middle; BORDER-RIGHT-WIDTH: 0px"
alt=gamma src="http://www.nature.com/__chars/gamma/black/med/base/glyph.gif">-
and <IMG
style="BORDER-TOP-WIDTH: 0px; BORDER-LEFT-WIDTH: 0px; BORDER-BOTTOM-WIDTH: 0px; VERTICAL-ALIGN: middle; BORDER-RIGHT-WIDTH: 0px"
alt=epsilon
src="http://www.nature.com/__chars/epsilon/black/med/base/glyph.gif">-proteobacteria.
</P>
<P class=lead>Chemolithotrophic bacteria, accounting for <IMG
style="BORDER-TOP-WIDTH: 0px; BORDER-LEFT-WIDTH: 0px; BORDER-BOTTOM-WIDTH: 0px; VERTICAL-ALIGN: baseline; BORDER-RIGHT-WIDTH: 0px"
alt=approx
src="http://www.nature.com/__chars/math/special/sim/black/med/base/glyph.gif">20
per cent of the bacterioplankton in sulphidic waters, created a buffer zone
between the toxic sulphidic subsurface waters and the oxic surface waters, where
fish and other nekton live. This is the first time that large-scale
detoxification of sulphidic waters by chemolithotrophs has been observed in an
open-ocean system. The data suggest that sulphide can be completely consumed by
bacteria in the subsurface waters and, thus, can be overlooked by remote sensing
or monitoring of shallow coastal waters. Consequently, sulphidic bottom waters
on continental shelves may be more common than previously believed, and could
therefore have an important but as yet neglected effect on benthic
communities.</P></DIV></FONT></DIV></BODY></HTML>