Significance, history, and challenges of environmental microbiology -- Formation of the biosphere : key biogeochemical and evolutionary events -- Physiological ecology : resource exploitation by microorganisms -- A survey of the earth's microbial habitats -- Microbial diversity : who is here and how do we know? -- Generating and interpreting information in environmental microbiology : methods and their limitations -- Microbial biogeochemistry : a grand synthesis -- Special and applied topics in environmental microbiology -- Future frontiers in environmental microbiology.