Detoxification of sulphidic African shelf waters by blooming chemolithotrophs Export

@article{citeulike:3779651, abstract = {Coastal waters support <90 per cent of global fisheries and are therefore an important food reserve for our planet. Eutrophication of these waters, due to human activity, leads to severe oxygen depletion and the episodic occurrence of hydrogen sulphide\&\#20;toxic to multi-cellular life\&\#20;with disastrous consequences for coastal ecosytems. Here we show that an area of <7,000\&\#9;km2 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. Combined chemical analyses, stoichiometric modelling, isotopic incubations, comparative 16S ribosomal RNA, functional gene sequence analyses and fluorescence in situ hybridization indicate that the detoxification proceeded by chemolithotrophic oxidation of sulphide with nitrate and was mainly catalysed by two discrete populations of \&\#179;- and \&\#181;-proteobacteria. Chemolithotrophic bacteria, accounting for <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.}, author = {Lavik, Gaute and St\"{u}hrmann, Torben and Br\"{u}chert, Volker and Van der Plas, Anja and Mohrholz, Volker and Lam, Phyllis and Mu{\ss}mann, Marc and Fuchs, Bernhard M. and Amann, Rudolf and Lass, Ulrich and Kuypers, Marcel M. M.}, citeulike-article-id = {3779651}, citeulike-linkout-0 = {http://dx.doi.org/10.1038/nature07588}, citeulike-linkout-1 = {http://dx.doi.org/10.1038/nature07588}, doi = {10.1038/nature07588}, issn = {0028-0836}, journal = {Nature}, keywords = {anammox, denitrification, geochemistry}, month = {December}, posted-at = {2009-01-29 11:05:59}, priority = {2}, publisher = {Nature Publishing Group}, title = {Detoxification of sulphidic African shelf waters by blooming chemolithotrophs}, url = {http://dx.doi.org/10.1038/nature07588}, year = {2008} }

TY - JOUR ID - citeulike:3779651 L3 - citeulike-article-id:3779651 N2 - Coastal waters support <90 per cent of global fisheries and are therefore an important food reserve for our planet. Eutrophication of these waters, due to human activity, leads to severe oxygen depletion and the episodic occurrence of hydrogen sulphide&#20;toxic to multi-cellular life&#20;with disastrous consequences for coastal ecosytems. Here we show that an area of <7,000&#9;km2 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. Combined chemical analyses, stoichiometric modelling, isotopic incubations, comparative 16S ribosomal RNA, functional gene sequence analyses and fluorescence in situ hybridization indicate that the detoxification proceeded by chemolithotrophic oxidation of sulphide with nitrate and was mainly catalysed by two discrete populations of &#179;- and &#181;-proteobacteria. Chemolithotrophic bacteria, accounting for <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. JF - Nature SN - 0028-0836 TI - Detoxification of sulphidic African shelf waters by blooming chemolithotrophs PB - Nature Publishing Group KW - anammox KW - denitrification KW - geochemistry AU - Lavik, Gaute AU - Stührmann, Torben AU - Brüchert, Volker AU - Van der Plas, Anja AU - Mohrholz, Volker AU - Lam, Phyllis AU - Mußmann, Marc AU - Fuchs, Bernhard AU - Amann, Rudolf AU - Lass, Ulrich AU - Kuypers, Marcel PY - 2008/12/10/ UR - http://dx.doi.org/10.1038/nature07588 ER -