Linking specific heterotrophic bacterial populations to bioreduction of uranium and nitrate in contaminated subsurface sediments by using stable isotope probing

Shifts in terminal electron-accepting processes during biostimulation of uranium-contaminated sediments were linked to the composition of stimulated microbial populations using DNA-based stable isotope probing. Nitrate reduction preceded U(VI) and Fe(III) reduction in [ 13 C]ethanol-amended microcosms. The predominant, active denitrifying microbial groups were identified as members of the Betaproteobacteria , whereas Actinobacteria dominated under metal-reducing conditions.