Book excerpt: This book highlights the current state-of-the-art of environmental molecular microbiology. International experts have contributed chapters that describe the various technologies and their applications in environmental microbiology. The first half of the book focuses on the microbial diversity and phylogeny of microorganisms in the environment and describes the molecular toolbox currently available for the study of the composition and diversity of microbial communities and their functions. Topics include the use of the 16S rRNA gene as a phylogenetic marker, metagenomics, metaproteomics, microa.