Starting a Winogradsky column

Winogradsky column
day 1

The concept of composting, to recycle the organic waste for growing new plants, is great. But traditional composting requires that you have a garden or at least some special containers outdoors or in the basement. Is there any other way to draw plant nutrients out of organic waste? Perhaps the method of bokashi would be a good alternative for people living in apartments? This form of composting is based on a mixture of microorganisms called EM (effective microorganism). You can buy dried formulas of EM, but why not make your own? The mixture contains three types of species, of which you can find two in the grocery store: baker yeast (Saccharomyces cerevisiae) and a particular kind of yogurt bacteria (Lactobacillus casei). The challange is to isolate the third organism, Rhodopseudomonas palustris. This bacteria is very common in mud. In order to isolate it I make a Winogradsky column.

Materials and method

In a vessel I blend:

• 30 ml pond mud
• 10 ml shredded toilet paper — as carbon source
• 10 ml gypsum — as sulfur source
• 1 ml chalk — as source of calcium carbonate in case the mud has low calcium amount

View sample origin in a larger map

After stirring all the ingredients together I put the blend on the bottom of a glass bottle. Then I put additional 50 ml mud on top of the previously mentioned blend. At last I fill almost all of the remaining space in the bottle with water from the pond. I cover the bottle with a lid and plastic foil fastened with a rubber band. The column will now stand on a windowsill for a month or two. My goal is to get layers of different species of bacteria in the bottle. Each weekend I'll post a photo showing how the experiment proceeds. After growing the bacteria I plan to isolate Rhodopseudomonas palustris from the column and grow it on a separate medium.

References

• B. Lidesten. Bakterier som använder ljus. Nationellt resurscentrum för biologi och bioteknik. (in Swedish)
• Wikipedia's article about Winogradsky column
• Winogradsky column: perpetual life in a tube — Edinburgh University
• G. Ç. DÖNMEZ, A. ÖZTÜRK, L. ÇAKMAKÇI. Properties of the Rhodopseudomonas palustris Strains Isolated From an Alkaline Lake in Turkey. Tr. J. of Biology. 23 (1999).