The article "Microorganisms Pumping Iron: Anaerobic Microbial Iron Oxidation and Reduction" by Karrie A. Weber, Laurie A. Achenbach, and John D. Coates discusses the role of microorganisms in iron redox reactions, particularly in anaerobic environments. Iron (Fe) is essential for life, and its redox cycling is crucial in soil and sedimentary environments. The authors highlight the importance of iron redox reactions in biogeochemical processes, such as mineral weathering, organic matter degradation, and the mobilization of contaminants. The article covers two main processes: microbial iron oxidation and microbial iron reduction. Microbial iron oxidation involves the conversion of Fe(II) to Fe(III), which can be facilitated by photoautotrophic and heterotrophic microorganisms. These processes are significant in both oxic and anoxic environments, contributing to the formation of banded iron formations (BIFs) in the Precambrian era. The article also discusses the role of specific microorganisms, such as *Dechloromonas agitata* and *Azospira sullium*, in perchlorate/chlorate-dependent Fe(II) oxidation, which could have implications for environmental contamination. Microbial iron reduction, on the other hand, involves the dissimilatory reduction of Fe(III) oxide minerals. This process is crucial for the biogeochemical cycling of iron and can be mediated by a diverse range of microorganisms, including members of the Archaea and Bacteria domains. The article explores the physiological mechanisms involved in Fe(III) reduction, including the use of conductive nanowires and electron shuttles to facilitate electron transfer to solid-phase Fe(III) oxides. The authors also discuss the biotechnological applications of these microbial processes, such as heavy-metal and radionuclide immobilization, and the potential for energy generation through microbial fuel cells. Overall, the article provides a comprehensive overview of the biogeochemical significance and ecological importance of microbial iron redox reactions.The article "Microorganisms Pumping Iron: Anaerobic Microbial Iron Oxidation and Reduction" by Karrie A. Weber, Laurie A. Achenbach, and John D. Coates discusses the role of microorganisms in iron redox reactions, particularly in anaerobic environments. Iron (Fe) is essential for life, and its redox cycling is crucial in soil and sedimentary environments. The authors highlight the importance of iron redox reactions in biogeochemical processes, such as mineral weathering, organic matter degradation, and the mobilization of contaminants. The article covers two main processes: microbial iron oxidation and microbial iron reduction. Microbial iron oxidation involves the conversion of Fe(II) to Fe(III), which can be facilitated by photoautotrophic and heterotrophic microorganisms. These processes are significant in both oxic and anoxic environments, contributing to the formation of banded iron formations (BIFs) in the Precambrian era. The article also discusses the role of specific microorganisms, such as *Dechloromonas agitata* and *Azospira sullium*, in perchlorate/chlorate-dependent Fe(II) oxidation, which could have implications for environmental contamination. Microbial iron reduction, on the other hand, involves the dissimilatory reduction of Fe(III) oxide minerals. This process is crucial for the biogeochemical cycling of iron and can be mediated by a diverse range of microorganisms, including members of the Archaea and Bacteria domains. The article explores the physiological mechanisms involved in Fe(III) reduction, including the use of conductive nanowires and electron shuttles to facilitate electron transfer to solid-phase Fe(III) oxides. The authors also discuss the biotechnological applications of these microbial processes, such as heavy-metal and radionuclide immobilization, and the potential for energy generation through microbial fuel cells. Overall, the article provides a comprehensive overview of the biogeochemical significance and ecological importance of microbial iron redox reactions.