Winogradsky column

 Winogradsky column

The Winogradsky column is a simple device for culturing a large diversity of microorganisms. Invented in the 1880s by Sergei Winogradsky, the device is a column of pond mud and water mixed with a carbon source such as newspaper (containing cellulose), blackened marshmallows 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 microorganisms such as Clostridium, Desulfovibrio, Chlorobium, Chromatium, Rhodomicrobium, and Beggiatoa, as well as many other species of bacteria, cyanobacteria, and algae.

The column provides numerous gradients, depending on additive nutrients, from which the variety of aforementioned organisms can grow. The aerobic water phase and anaerobic mud or soil phase are one such distinction. Because of oxygen's low solubility in water, the water quickly becomes anoxic towards the interface of the mud and water. Anaerobic phototrophs are still present to a large extent in the mud phase, and there is still capacity for biofilm creation and colony expansion, as shown in the images at right. Algae and other aerobic phototrophs are present along the surface and water of the upper half of the columns.

How to make a Winogradsky Column

Materials

• Bucket 

• Shovel

• Spoon

• Bowls

• Tall jar or plastic bottle or tennis ball canister

• Scissors

• Plastic wrap

• Rubber band

Basic ingredients

• Mud (source of microbes)

• Water (source of microbes)

• Egg yolk (sulfur source)

• Newspaper (carbon source)

• Sunlight or Lamp (light source)

Other ingredients to try

• Straw

• Leaves

• Bark

• Metal

• Shells

• Insect parts

• Salt

• Epsom salts

• Acid source

• Alkaline source

Instructions

1. Draw a line on your bottle at about ¼ from the top and then another line at about ¼ from the bottom.

2. Go out and collect some mud and water.

3. Cut the newspaper into small pieces.

4. In a small mixing bowl, add the egg yolk (raw or hard-boiled) and newspaper and a small amount of mud, at least as much to fill the bottle ¼ of the way. If you are including additional ingredients, add them to this mixture.

5. Fill the bottle ¼ way with the mud, egg yolk, newspaper mixture.

6. Add mud to the top line.

7. Add water almost to the top. Leave a small amount of space.

8. Cover the column with plastic wrap and a rubber band (do not put a tight lid on because it may explode due to gases released by the microbes).

9. Set it in the sunlight or under a lamp.

10. Let your column go and watch for changes over the next 4 to 8 weeks. Take pictures of the changes and share them with me on Twitter.

資料來源:

https://en.wikipedia.org/wiki/Winogradsky_column

https://en.wikipedia.org/wiki/Sergei_Winogradsky

https://joyfulmicrobe.com/winogradsky-column/