ABSTRACT
This chapter examines the state of the art of soil metagenomics approaches, addresses both the technical achievements and challenges, and the progress made with respect to our understanding of soil microbial diversity and function. Soil metagenomics provides a unique access route to the genes present in the genomes of uncultured soil organisms, offering a broad spectrum of parameters of soil microbial communities, ranging from single genes to metabolic pathways and/or to entire genome reconstructions. Understanding the interactions between different soil organisms and their surrounding environment, that is, linking microbial communities to their ecological roles and functions is an important task in soil science. Microbial genomes represent large gene pools and thus constitute rich resources for agricultural, pharmaceutical, and industrial biotechnology. Functional or activity-based screening is achieved through selection for a phenotype, which can be an enzymatic activity or a metabolite produced by the library clones.
