Prokaryotic microorganisms in uranium mining waste piles and their interactions with uranium and other heavy metals The influence of uranyl and sodium nitrate under aerobic and anaerobic conditions on the microbial community structure of a soil sample from the uranium mining waste pile Haberland in Germany was studied by using the 16S rRNA gene retrieval. The results demonstrate a shifting in the bacterial populations depending on the treatment whereas the archaeal community was changed independently of the treatment. By using the nitrate reductase gene (narG) as a functional marker it was additionally demonstrated that some of the bacteria stimulated possess the membrane bound nitrate reductase.two Arthrobacter strains were isolated which tolerate relatively high concentrations of uranium and heavy metals. These strains are able to precipitate lead as lead sulphide (galena) or lead phosphate mineral phase (pyromorphite) depending on their physiological state and to accumulate uranium intracellularly. The results demonstrate a microbial community in the uranium mining waste pile Haberland which is able to influence the fate of uranium.