Final answer:
Bioremediation of uranium depends on metal-reducing bacteria, which convert soluble, oxidized uranium into an insoluble, reduced form, thus immobilizing it and preventing groundwater contamination.
Step-by-step explanation:
Bioremediation of uranium depends primarily on metal-reducing bacteria. Microbial bioremediation makes use of prokaryotes or microbial metabolism to remove pollutants, including various toxic metals. For instance, certain species of bacteria are capable of converting toxic mercury into its nontoxic form. Similarly, metal-reducing bacteria are known for their ability to transform uranium from its oxidized form, which is soluble and mobile, into its reduced form, which is insoluble and less likely to contaminate groundwater.
These bacteria, for example, Geobacter and Shewanella species, actively carry out the reduction process, thereby immobilizing the uranium and rendering it less harmful. This process is important in the bioremediation of sites contaminated by uranium, such as those impacted by nuclear industry operations or mining activities.