WINOGRADSKY COLUMNS

Winogradsky columns were originally designed to grow bacteria in a mini-ecosystem that replicate the natural environment. Sergei Winogradsky was interested in growing bacteria that did not normally grow on agar plates and came up with the idea to try to grow these bacteria in a column. The setup of a Winogradsky column is easy and only requires a few components. In order to maximize the colors and growth in your column, you should have these five things:

1. Water

2. Mud (with organic matter)

3. Air

4. Sunlight

5. Source of sulfur

The microbes that grow in Winogradsky columns are not all Bacteria. Some are microbial eukaryotes like amoeba, ciliates, or photosynthetic algae, and some can be Archaea, another group of single-celled microbes. All of these organisms are naturally present in mud and pond or river water and will grow in your column if conditions are right.

There is one important thing to remember when assembling your Winogradsky column. The order of assembly matters. The column shape works best for growing different types of organisms because it is tall. Organisms have plenty of room to find their niche and grow without being disturbed by others nearby. At each depth within the column, nutrients and energy sources will be produced and consumed by each group of organisms, and eventually they will create a stable ecosystem, or "biosphere". At the bottom of the column, most or all of the oxygen in the air will be used up by the time it diffuses down that far, so this is where we provide an alternative (sulfur) for anaerobic microbes to flourish. With oxygen at the top and sulfur at the bottom, plus sunlight, we ensure there is plenty of energy for the Winogradsky microbes to use. The last thing they need is a source of carbon, or organic matter, which is sourced from the mud. We can also mix in some shredded newspaper or leaves to give additional food if needed. After you have placed your source of sulfur (boiled egg yolk works great), add plenty of mud, fill it almost all the way with water, and leave some air at the top. Cap your column and place it in a sunny window. 

It will take at least 1-2 weeks before you begin to notice any changes, but you will see pinks and purples appear toward the bottom and greens appear near the top. These colors reflect the different light-harvesting pigments used by various photosynthetic organisms.