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...