由RV Alexander von Humbolt在納米比亞沿海水域獲得數(shù)據(jù)顯示,，由含硫化物的海水覆蓋的面積大約為7000平方公里的一個(gè)非洲沿海大陸架區(qū)域,，因細(xì)菌的作用而消除了毒性：對(duì)生物有害的硫化物被氧化成無(wú)毒的膠體硫和硫酸鹽。

沿海水域的富營(yíng)養(yǎng)化（經(jīng)常是由人類(lèi)活動(dòng)引起的）會(huì)導(dǎo)致藻類(lèi)繁盛,，引起氧的嚴(yán)重消耗和硫化氫的間歇性出現(xiàn),，對(duì)生態(tài)系統(tǒng)產(chǎn)生災(zāi)難性后果。關(guān)于硫化物會(huì)被亞表層海水中的細(xì)菌完全耗盡,、從而會(huì)被淺層沿海水域的遙感或監(jiān)測(cè)活動(dòng)忽略的發(fā)現(xiàn)表明,，大陸架上含硫化物的海底水域也許要比我們所想的更普遍，所以有可能對(duì)底棲生物群落產(chǎn)生一個(gè)重要的,、但以前卻被忽略的影響,。(生物谷Bioon.com)

生物谷推薦原始出處：

Nature 457, 581-584 (29 January 2009) | doi:10.1038/nature07588

Detoxification of sulphidic African shelf waters by blooming chemolithotrophs

Gaute Lavik1,5, Torben Stührmann1,5, Volker Brüchert1,6, Anja Van der Plas2, Volker Mohrholz3, Phyllis Lam1, Marc Mumann4, Bernhard M. Fuchs1, Rudolf Amann1, Ulrich Lass3 & Marcel M. M. Kuypers1

1 Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359 Bremen, Germany
2 National Marine Information & Research Centre Ministry of Fisheries & Marine Resources, PO Box 912, Swakopmund, Namibia
3 Baltic Sea Research Institute Warnemünde, Seestrasse 15, D-18119 Rostock, Germany
4 Department of Microbial Ecology, Vienna Ecology Centre, University of Vienna, Althanstrae 14, A-1090 Vienna, Austria

Coastal waters support 90 per cent of global fisheries and are therefore an important food reserve for our planet1. 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 ecosytems2, 3, 4, 5. Here we show that an area of 7,000 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 - and -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.