ABSTRACT
The metabolism and the survival of soil microorganisms are strongly influenced by the availability of water and nutrients. In contrast to aquatic habitats, surfaces of soil environments undergo dramatic cyclic changes in water content, ranging from water saturation to extreme aridity. One emerging tool that draws together traditional soil biology and modern molecular biology is metagenomics which entails collective analysis of genomes of an assemblage of microorganisms. The chemical composition of soil is derived from a combination of its geologic and biologic origins. In the ensuing years, microbiologists dedicated intense effort to describe the phylogenetic diversity of exotic, ordinary environments ocean surfaces, deep sea vents, hot springs, soil, animal rumen, gut, human oral cavity and intestine. Fluorescent antibody studies require prior knowledge and culturing of an organism or one closely related to it to raise antibodies.
