Journal article
Presence, distribution, and diversity of iron-oxidizing bacteria at a landfill leachate-impacted groundwater surface water interface
We examined the presence of iron-oxidizing bacteria (IOB) at a groundwater surface water interface (GSI) impacted by reduced groundwater originating as leachate from an upgradient landfill. IOB enrichments and quantifications were obtained, at high vertical resolution, by an iron/oxygen opposing gradient cultivation method.
The depth-resolved soil distribution profiles of water content, Fe2+, and total Fe indicated sharp gradients within the top 10 cm sediments of the GSI, where the IOB density was the highest. In addition, the vertical distribution of iron-reducing bacteria at the same sampling site mirrored the IOB distribution.
Clone libraries from two separate IOB enrichments indicated a stratified IOB community with clear differences at short vertical distances. Alpha- and Betaproteobacteria were the dominant phylotypes. Clones from the near-surface sediment (1-2 cm below ground surface) were dominated by members of the Bradyrhizobiaceae and Comamonadaceae; clones from the deeper sediments were phylogenetically more diverse, dominated by members of the Rhodocyclaceae.
The iron deposition profiles indicated that active iron oxidation occurred only within the near-to-surface GSI sediments. The match between the iron deposition profiles and the IOB abundance profiles strongly hints at the contribution of the IOB community to Fe oxidation in this Fe-rich GSI ecosystem.
Language: | English |
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Year: | 2010 |
Pages: | 260-271 |
ISSN: | 15746941 and 01686496 |
Types: | Journal article |
DOI: | 10.1111/j.1574-6941.2009.00797.x |
ORCIDs: | Smets, Barth F. |