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Microenvironments and microbial community structure in sediments
Author(s) -
Tankéré S. P. C.,
Bourne D. G.,
Muller F. L. L.,
Torsvik V.
Publication year - 2002
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1046/j.1462-2920.2002.00274.x
Subject(s) - sediment , redox , environmental chemistry , eutrophication , total organic carbon , biofilm , oxygen , sediment–water interface , biology , bottom water , ecology , oceanography , chemistry , geology , bacteria , inorganic chemistry , nutrient , paleontology , organic chemistry
Summary The aim of this study was to explore the potential of a combined chemical and microbiological approach as part of a study of organic carbon oxidation processes in sediments. An assessment of microbiological diversity using molecular techniques was carried out in combination with high resolution chemical measurements at the sediment–water interface of a coastal lagoon affected by eutrophication in autumn 2000. There was a 0.2 mm overlap between the O 2 and H 2 S profiles. pH showed a maximum just above the sediment–water interface coinciding with an oxygen maximum, suggesting photosynthetic activity, and a minimum coinciding with the O 2 –H 2 S interface. The redox potential was high in bottom water and surface sediment, reflecting the presence of oxygen and oxides, and reached low values after a step‐wise decrease at − 18 mm. Reduction of Fe occurred within the biofilm at the O 2 –H 2 S interface and was mostly due to reduction by H 2 S. The elevated concentrations of dissolved Mn in the oxic water may have been caused either by in situ production within organic aggregates or lateral water flow from sites nearby at which Mn 2 + diffuses out of the sediment. Sequences related to sulphur chemolitotrophs were retrieved from the biofilm samples, which is consistent with the small overlap between O 2 and H 2 S observed in this biofilm. Although the resolution of techniques used was different, sequencing results were consistent with chemical data in delineating the same horizons according to redox, pH or ecological properties.