Cupriavidus metallidurans

Cupriavidus metallidurans strain CH34 (renamed from Ralstonia metallidurans and previously known as Ralstonia eutropha and Alcaligenes eutrophus) is a non-spore-forming, Gram-negative bacterium which is adapted to survive several forms of heavy metal stress. Therefore, it is an ideal subject to study heavy metal disturbance of cellular processes. This bacterium shows a unique combination of advantages not present in this form in other bacteria. Also it plays a vital role, together with the species Delftia acidovorans, in the formation of gold nuggets, by precipitating metallic gold from a solution of gold(III) chloride, a compound highly toxic to most other microorganisms.