Microbial communities in extreme environments and their interactions with uranium and other xenobiotics

Bacteria are the most ubiquitous organisms in all terrestrial and aquatic environments. The talk will focus on cell wall dependent accumulation and biomineralization of uranium by particular Gram-positive and Gram-negative bacteria recovered from different extreme habitats. By using TEM, EXAFS and TRLF we were able to demonstrate that the Gram-negative and most of the Gram-positive bacteria inhabiting oligotrophic environments such as deep subsurface layers or heavy metal and pesticides polluted industrial sites immobilize U(VI) at their cell walls or extracellularly in a form of uranyl phosphate compounds. Some of the isolates demonstrated high capability to utilize phenol compounds as well. These properties of the studied extremophile bacterial isolates are promising for development of bioremediation approaches for heavy metal and phenol polluted environments