Minerals and Aqueous Species of Iron and Manganese as Reactants and Products of Microbial Metal Respiration.- Energetic and Molecular Constraints on the Mechanism of Environmental Fe(III) Reduction by Geobacter.- Biochemistry of Extracellular Respiration in Shewanella oneidensis.- On the Role of Endogenous Electron Shuttles in Extracellular Electron Transfer.- Humic Substances and Extracellular Electron Transfer.- Metal Reducers und Reduction Targets. A Short Survey about the Distribution of Dissimilatory Metal Reducers and the Multitude of Terminal Electron Acceptors.- Metal Reduction as a Tool in Bioremediation Processes.- Dissimilatory Metal Reducers Producing Electricity.- Microbial Fuel Cells.