Bacterial interaction with precious metals

• Applicant: Professor Dr. Dietrich H. Nies
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2010 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 172323474

The precious metals gold, silver and copper occur in their ionic oxidation states {Au(III), Au(I), Ag(I), Cu(II), Cu(I)} and as free metals in bacterial environments. Understanding bacterial transformations of these metals and ions will shed light on a range of processes such as the supergene formation of secondary minerals and the killing of pathogenic bacteria on metallic copper surfaces. The metal resistant bacterium C. metallidurans seems to catalyze formation of gold particles by active biochemical processes. Copper-specific factors (Cop) may be involved in these reactions. In the proposed project we will evaluate the gold-specific reactions catalyzed by individual Cop factors. By doing so, we will also learn from gold-specific reactions more about copper detoxification in this bacterium, because gold has no micronutrient function in cells and is primarily speciated as Au(I) or metallic gold in the periplasm. On the other hand, mutant strains of E. coli will be used as test systems to study the physiological function of Cop factors, and this will yield insights into the interaction of E. coli with Cu(II), Cu(I) and metallic copper.

• DFG Programme: Research Grants
• International Connection: Australia
• Participating Persons: Dr. Cornelia Große; Dr. Frank Reith