This book provides an in-depth review of the ultrastructure of the phototrophic bacteria and how electron microscopy is used in the study of light-harvesting antennae and reactions centers, as well as ecology. Topics discussed include detailed methods and models for the three basic types of photosynthetic apparatus. The thylakoid (cyanobacteria), intracytoplasmic chromatophore membrane (purple bacteria), and chlorosome (green bacteria) models are presented based on ultrastructural studies including ultra-thin sections, 3-D reconstruction of thick sections, freeze-fracture replicates, and immunolabeling. The book also explains how species of phototrophic bacteria can be identified in natural populations by their ultrastructure. Structure of Phototrophic Prokaryotes will be an invaluable reference resource for researchers and students working in photosynthesis and microbial ecology.