The below mentioned article provides a note on winogradsky column, explained with the help of a suitable diagram.
The Winogradsky column is a glass or clear plastic cylinder with a core of solid or sediment in it. This model system employed to study the growth of specific microorganisms, has been named after a noted Russian microbiologist Sergei Winogradsky. Specific microbial population grows at different levels due to different environmental conditions. The column is exposed to light so that different photosynthetic populations develop.
Algae and cyanobacteria which are oxygenic photosynthetic microorganisms grow at the surface. At the lower levels are anaerobic green and purple sulphur bacteria while obligately anaerobic heterotrophs appear at the lowest levels of the column.