Expression of acetate permease-like (apl ) genes in subsurface communities of Geobacter species under fluctuating acetate concentrations.

TitleExpression of acetate permease-like (apl ) genes in subsurface communities of Geobacter species under fluctuating acetate concentrations.
Publication TypeJournal Article
Year of Publication2010
AuthorsElifantz H, N'guessan LA, Mouser PJ, Williams KH, Wilkins MJ, Risso C, Holmes DE, Long PE, Lovley DR
JournalFEMS Microbiol Ecol
Volume73
Issue3
Pagination441-9
Date Published2010 Sep
ISSN1574-6941
KeywordsAcetates, Bacterial Proteins, Biodegradation, Environmental, Fresh Water, Gene Expression Regulation, Bacterial, Gene Library, Geobacter, Membrane Transport Proteins, Multigene Family, RNA, Bacterial, Uranium, Water Pollutants, Radioactive
Abstract

The addition of acetate to uranium-contaminated aquifers in order to stimulate the growth and activity of Geobacter species that reduce uranium is a promising in situ bioremediation option. Optimizing this bioremediation strategy requires that sufficient acetate be added to promote Geobacter species growth. We hypothesized that under acetate-limiting conditions, subsurface Geobacter species would increase the expression of either putative acetate symporters genes (aplI and aplII). Acetate was added to a uranium-contaminated aquifer (Rifle, CO) in two continuous amendments separated by 5 days of groundwater flush to create changing acetate concentrations. While the expression of aplI in monitoring well D04 (high acetate) weakly correlated with the acetate concentration over time, the transcript levels for this gene were relatively constant in well D08 (low acetate). At the lowest acetate concentrations during the groundwater flush, the transcript levels of aplII were the highest. The expression of aplII decreased 2-10-fold upon acetate reintroduction. However, the overall instability of acetate concentrations throughout the experiment could not support a robust conclusion regarding the role of apl genes in response to acetate limitation under field conditions, in contrast to previous chemostat studies, suggesting that the function of a microbial community cannot be inferred based on lab experiments alone.

DOI10.1111/j.1574-6941.2010.00907.x
Alternate JournalFEMS Microbiol. Ecol.
PubMed ID20533942