1. Oxygen and Nitrate Respiration in Streptomyces Coelicolor A3(2)R. Gary Sawers, Dorte Falke and Marco Fischer2. Anaerobic Metabolism in Haloferax Genus: Denitrification as Case of StudyJavier Torregrosa-Crespo, Rosa Maria Martinez-Espinosa, Julia M Esclapez, Vanesa Bautista, Carmen Pire, Monica Camacho, David J. Richardson and Maria Jose Bonete 3. Mechanisms of Bacterial Extracellular Electron ExchangeGaye F. White, Marcus J. Edwards, Laura Gomez-Perez, David J. Richardson, Julea N. Butt and Thomas A. Clarke4. Cooperation of Secondary Transporters and Sensor Kinases in Transmembrane Signaling: The DctA/DcuS or DcuB/DcuS Sensor Complexes of Escherichia ColiGottfried Unden, Sebastian Worner and Christian Monzel5. Pivotal Role of Iron in the Regulation of Cyanobacterial Electron TransportAndres Gonzalez, Emma Sevilla, M. Teresa Bes, M. Luisa Peleato and Maria F. Fillat6. Bacterial Electron Transfer Chains Primed by ProteomicsHans J.C.T. Wessels, Naomi M. de Almeida, Boran Kartal and Jan T. Keltjens7. Nitrous Oxide Metabolism in Nitrate-Reducing Bacteria: Physiology and Regulatory MechanismsMaria J. Torres, Jorg Simon, Gary Rowley, Eulogio J. Bedmar, David J. Richardson, Andrew J. Gates and Maria J. Delgado8. The Model [NiFe]-Hydrogenases of Escherichia ColiFrank Sargent