Predicting Microbial Interactions Could Improve Uranium Bioremediation


Advances in genome sequencing and the capability to develop genome-scale metabolic models have enabled the ability to predict microbial interactions. An analysis of two microbes known to compete in situ during tests of uranium bioremediation predicts how life strategies and growth rates for each are altered by substrate and nutrient availability and the implications of these interactions on uranium bioremediation strategies. DOE researchers from the University of Massachusetts and University of Toronto working with metabolic models for two metal-reducing microorganisms (Rhodoferax and Geobacter) present in the subsurface at a uranium bioremediation test site in Rifle, CO, explain how the introduction of acetate and the availability of ammonium impacts growth rates and the life strategies of these two organisms. Acetate addition in the absence of ammonium favors Geobacter metabolism consistent with field observations. However, the models predict that Rhodoferax metabolism should be favored in the presence of ammonium due to a higher overall growth rate. The results help explain field observations of decreased uranium bioreduction activity in areas with elevated ammonium concentrations. Unlike Geobacter species, Rhodoferax species are not known to reduce uranium indicating ammonium concentration as an important design criterion for uranium bioremediation.


Zhuang, K., M. Izallalen, P. Mouser, H. Richter, C. Risso, R. Mahadevan, and D. R. Lovley. 2011. The ISME Journal 5, 305-16.