Open AccessPresence, distribution, and diversity of iron‐oxidizing bacteria at a landfill leachate‐impacted groundwater surface water interface
Author(s) -
Yu Ran,
Gan Ping,
MacKay Allison A.,
Zhang Shouliang,
Smets Barth F.
Publication year - 2010
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2009.00797.x
Subject(s) - leachate , biology , groundwater , bacteria , oxidizing agent , surface water , distribution (mathematics) , environmental chemistry , ecology , environmental engineering , environmental science , mathematical analysis , mathematics , organic chemistry , engineering , chemistry , geotechnical engineering , genetics
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, Fe 2+ , 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.