Chemoautotrophic Origin of Life: The Iron-Sulfur World Hypothesis -- Evolution of Metabolic Pathways and Evolution of Genomes -- Novel Cultivation Strategies for Environmentally Important Microorganisms -- Environmental Proteomics: Studying Structure and Function of Microbial Communities -- Analysis of Microbial Communities by Functional Gene Arrays -- Probing Identity and Physiology of Uncultured Microorganisms with Isotope Labeling Techniques -- The Geomicrobiology of Arsenic -- Bioinformatics and Genomics of Iron- and Sulfur-Oxidizing Acidophiles -- The Geomicrobiology of Catastrophe: A Comparison of Microbial Colonization in Post-volcanic and Impact Environments -- Microbial Diversity of Cave Ecosystems -- Statistical Evaluation of Bacterial 16S rRNA Gene Sequences in Relation to Travertine Mineral Precipitation and Water Chemistry at Mammoth Hot Springs, Yellowstone National Park, USA -- Compositional, Physiological and Metabolic Variability in Microbial Communities Associated with Geochemically Diverse, Deep-Sea Hydrothermal Vent Fluids -- The Molecular Geomicrobiology of Bacterial Manganese(II) Oxidation -- Role of Microorganisms in Banded Iron Formations -- Synergistic Roles of Microorganisms in Mineral Precipitates Associated with Deep Sea Methane Seeps -- Bacterial Degradation of Polychlorinated Biphenyls -- Role of Clay and Organic Matter in the Biodegradation of Organics in Soil -- Electrodes as Electron Acceptors, and the Bacteria Who Love Them -- The Biogeochemistry of Biomining. This book is an interdisciplinary review of recent developments in topics including origin of life, microbial-mineral interactions, and microbial processes functioning in marine and terrestrial environments. A major component of this book addresses molecular techniques to evaluate microbial evolution and assess relationships of microbes in complex, natural communities. The function of microbial community members and their possible geological impact are evaluated from a perspective of (meta)genomics, (meta)proteomics, and isotope labeling. As well as summarizing current knowledge in various areas, it also reveals unresolved questions that require future investigations. These chapters enhance our fundamental knowledge of geomicrobiology that contributes to the exploitation of microbial functions in mineral and environmental biotechnology applications. Authors have provided skillful reviews and outlined unique perspectives on environmental microorganisms and their related processes.