Journal
ISME JOURNAL
Volume 7, Issue 2, Pages 370-383Publisher
SPRINGERNATURE
DOI: 10.1038/ismej.2012.109
Keywords
Geobacter; arsenic respiration; arsenic resistance; gene transcription; uranium bioremediation
Categories
Funding
- Office of Science (BER), US Department of Energy [DE-SC0004080, DE-SC0004814, DE-FC02-02ER63446]
- Integrated Field Research Challenge Site (IFRC) at Rifle, CO, USA
- Lawrence Berkeley National Laboratory's Sustainable Systems Scientific Focus Area
- US Department of Energy (DOE), Office of Science, Office of Biological and Environmental Research [DE-AC02-05CH11231]
Ask authors/readers for more resources
The possibility of arsenic release and the potential role of Geobacter in arsenic biogeochemistry during in situ uranium bioremediation was investigated because increased availability of organic matter has been associated with substantial releases of arsenic in other subsurface environments. In a field experiment conducted at the Rifle, CO study site, groundwater arsenic concentrations increased when acetate was added. The number of transcripts from arrA, which codes for the a-subunit of dissimilatory As(V) reductase, and acr3, which codes for the arsenic pump protein Acr3, were determined with quantitative reverse transcription-PCR. Most of the arrA (>60%) and acr3-1 (>90%) sequences that were recovered were most similar to Geobacter species, while the majority of acr3-2 (>50%) sequences were most closely related to Rhodoferax ferrireducens. Analysis of transcript abundance demonstrated that transcription of acr3-1 by the subsurface Geobacter community was correlated with arsenic concentrations in the groundwater. In contrast, Geobacter arrA transcript numbers lagged behind the major arsenic release and remained high even after arsenic concentrations declined. This suggested that factors other than As(V) availability regulated the transcription of arrA in situ, even though the presence of As(V) increased the transcription of arrA in cultures of Geobacter lovleyl, which was capable of As(V) reduction. These results demonstrate that subsurface Geobacter species can tightly regulate their physiological response to changes in groundwater arsenic concentrations. The transcriptomic approach developed here should be useful for the study of a diversity of other environments in which Geobacter species are considered to have an important influence on arsenic biogeochemistry. The ISME Journal (2013) 7, 370-383; doi:10.1038/ismej.2012.109; published online 4 October 2012
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available