Final Spring Winogradsky Column Report

Column description
My spring Winogradsky column has left a lot to be desired. There has been very little noticible activity after the cheese turned white, other than a very strong odor coming from the column and forcing me to put it outside. Unlike my previous columns from the fall, this column resulted in few changes in color throughout the ten weeks of the experiment.

Materials and Methods
I used the method described from the Penn State profile: http://www.personal.psu.edu/faculty/j/e/jel5/biofilms/winogradsky.html.

• One column constructed of soil or mud from virtually any source
• Water from the same or a different source
• To these natural components, are added supplemental carbon and sulfur.
• Above the soil is a layer of water and the column is usually covered to retard evaporation.
• The entire column is then illuminated to encourage the growth of phototrophs.

For materials, I used:

• Mud from a backyard puddle
• Puddle water
• Glass vase
• Cut grasses for the carbon source
• Cheese for the sulfer source

Results
Amost immediately the cheese in the middle of the column turned extemely white and has remained so for the entire 10 week experiment. I suggested that these might be some form of fungi - or some form of chemoorganoheterotrophs because they are feeding on organic carbon, light as well as the carbon, and using the carbon for their e- source. I saw no sign of the green or rust colored activity that was so prevalent in my column last semester.

On the surface of the water a thin layer of white biofilm and strong oder began within the first three weeks. Since, the water in the column has overflowed once and the film has turned green with a spiderweb-like subsistance. According to the Microbial World website by Jim Deacon, the layer of biofilm on the surface should be sheathed bacteria.

Conclusion
Considering that there were few other signs of life beyond the cheese fungus, the environment in my column might have been too extreme. I did not take a ph sample, but this might have given me an idea of what the reasons for such little activity were. Possibly the sheathed bacteria were better protected to survive in my tiny extreme environment. For a classroom activity, I liked using a smaller container for myself, but I think that the larger columns would be easier to deal with with children. Also, I would want to have one or more controls available and mud from different environments as well as other carbon and sulfer sources. Possibly I simply did not provide enough cut grass for carbon nutrients.