Winogradsky column

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The Winogradsky Column is a simple device for culturing a large diversity of microorganisms. Invented by Sergei Winogradsky (1856-1953), the device is a column of pond mud and water mixed with a carbon source such as newspaper (containing cellulose or egg-shells (containing calcium carbonate) and a sulfur source such as gypsum (calcium sulfate) or egg-yolk. Incubating the column in sunlight for months results in an aerobic/anaerobic gradient as well as a sulfide gradient. These two gradients promote the growth of different micro-organisms such as clostridium, desulfovibrio, chlorobium, chromatium, rhodomicrobium, beggiatoa, as well as many other species of bacteria, cyanobacteria, and algae.

[edit] Construction

The column is only a rough mixture of ingredients; more or less of any of these elements will still produce a good culture. You do not have to worry over exact measurements.

Obtain a tall glass or plastic tube 30cm long by 5cm wide or more
Obtain mud from a pond, remove sticks and other debris
Obtain water from a pond
Add ~0.25% of calcium carbonate by weight to the mud. Ground egg-shells as well as over the counter antacids such as Maalox or Mylanta are both sources of calcium-carbonate
Add ~0.50% of calcium sulfate or sodium sulfate by weight to the mud. Egg-yolks are a good source of sulfur
Add some shredded newspaper or hay as a cellulose source to the mud
Mix the mud solution and fill the container about ~1/3 full. Do not allow air-pockets to form in this layer as it is meant to be anerobic.
Add mud without the calcium carbonate and calcium sulfate sources until the column is ~2/3 full. Again, do not allow air-pockets to form.
Add the pond water until the column is ~5/6 full
Cover the column with a cap or plastic wrap and seal
Place the column in a window where it will receive good light
Incubate for several months