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The Winogradsky Column as a Window on the Past
As we view new wonders of the world, climb to new heights and plunge to new depths, we see not only some amazing sights but we
also increase the range of biodiversity and see yet a new angle on evolution. One particular example are hydrothermal vents, first observed when the submersible vehicle Alvin explored the Mid-Atlantic
spreading ridge where the North American and European plates are inexorably moving apart.
When looked at closely, this highly volcanic environment is a mirror of what is occurring in the Winogradsky Column, albeit at lower temperatures. Sulfates are being reduced and elemental sulfur is being
bound into sulfate salts. Ancient bacteria, Extremophiles, that are not dissimilar to the anaerobic bacteria accomplishing their task in the column at lower temperatures, are doing all of this at high
temperatures deep in the ocean where it was once believed no life existed.
As well, it is a window on the past. In a recent article in Nature, Euan Nisbet paints a picture of an environment of early organisms in the Archean period 2.5 to 4 billion years ago that are analogs to those
found in hydrothermal vents. They did the same work of the deep ocean vents of today cycling metals, CO2 and sulfur.
In a sense, by creating a Winogradsky Column we are reclaiming the ancient environments of the past.
Further Questions
There are a number of other areas that can be investigated and as an activity with students it is, in fact, limitless in scope of what might be accomplished.
- If a protist population is established in a series of columns, what effect will the development/succession of the column have on it? Is there a relationship between the protist population and the cycling
of sulfur? What might happen if the growth of the column were suppressed?
- Do the columns generate energy? Would a small light bulb light? Why might this occur? Where does the energy come from for the bacteria?
- How barren a soil can there be before no growth will occur?
- If iron is increased how might that affect the population diversity?
- Are there methanogens in the column? How would they be detected? How might their growth be enhanced?
Conclusions
As can be seen the Winogradsky Column is a far more complex and fascinating system than it seems at first glance. It is an excellent example of an
investigation that can span the level from guided inquiry all the way to very opened ended projects that can keep students investigating for months. As well, it is a window on the biodiversity of our
world. Microbes are poorly documented and very misunderstood. The Winogradsky column is an excellent way to show students that in a sense as we investigate what is growing in the columns we are investigating
our world and ourselves.
References
Atlas and Bartha Microbial Ecology 3rd ed. Benjamin Cummings 1993 563 pp.
Burns and Slater Experimental Microbiology Blackwell Scientific, 1982
Hudson, Barbara K. Microbiology in Today’s World 2nd ed. Kendall-Hunt Publishing 1998
Madigan, Martinko and Parker, Brock Biology of Microorganisms 9th ed Prentice-Hall Publishing, 2000
Nisbet, Euan “The Realms of Archaean Life” Nature vol. 405, 8 June 2000 pp 625-6.
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