This Winogradsky column web page is designed to teach undergraduate students a simple model system of nutrient cycling in natural waters. It includes a physical description of the column and explains how the column can be used to demonstrate metabolic diversity of prokaryotes, how microorganisms occupy highly specific microsites according to their environmental tolerances and their carbon and energy requirements, and how mineral elements are cycled in natural environments. Artistic illustrations and images illustrate the interdependent roles of microorganisms.
