nerc.ac.uk

Biological and chemical sulfide oxidation in a Beggiatoa inhabited marine sediment

Preisler, André; de Beer, Dirk; Lichtschlag, Anna; Lavik, Gaute; Boetius, Antje; Jørgensen, Bo Barker. 2007 Biological and chemical sulfide oxidation in a Beggiatoa inhabited marine sediment. The ISME Journal, 1 (4). 341-353. 10.1038/ismej.2007.50

Full text not available from this repository. (Request a copy)

Abstract/Summary

The ecological niche of nitrate-storing Beggiatoa, and their contribution to the removal of sulfide were investigated in coastal sediment. With microsensors a clear suboxic zone of 2-10 cm thick was identified, where neither oxygen nor free sulfide was detectable. In this zone most of the Beggiatoa were found, where they oxidize sulfide with internally stored nitrate. The sulfide input into the suboxic zone was dominated by an upward sulfide flux from deeper sediment, whereas the local production in the suboxic zone was much smaller. Despite their abundance, the calculated sulfide-oxidizing capacity of the Beggiatoa could account for only a small fraction of the total sulfide removal in the sediment. Consequently, most of the sulfide flux into the suboxic layer must have been removed by chemical processes, mainly by precipitation with Fe2+ and oxidation by Fe(III), which was coupled with a pH increase. The free Fe2+ diffusing upwards was oxidized by Mn(IV), resulting in a strong pH decrease. The nitrate storage capacity allows Beggiatoa to migrate randomly up and down in anoxic sediments with an accumulated gliding distance of 4 m before running out of nitrate. We propose that the steep sulfide gradient and corresponding high sulfide flux, a typical characteristic of Beggiatoa habitats, is not needed for their metabolic performance, but rather used as a chemotactic cue by the highly motile filaments to avoid getting lost at depth in the sediment. Indeed sulfide is a repellent for Beggiatoa.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1038/ismej.2007.50
ISSN: 17517362
Date made live: 12 Sep 2012 12:28 +0 (UTC)
URI: http://nora.nerc.ac.uk/id/eprint/442681

Actions (login required)

View Item View Item

Document Downloads

Downloads for past 30 days

Downloads per month over past year

More statistics for this item...