Winogradsky Column Experiment

You MUST set this up ASAP in order for it to have the minimum 8 weeks of good weather to grow prior to writing your paper on your column. Click here for the instructions.(feel free to google “Winogradsky Column” for additional information, this is a very common experiment to assign, but know that I run everything through TurnItIn.com , so online resources can help you setup your column and understand your results, but YOU MUST DO THE 8 WEEK LONG EXPERIMENT TO OBTAIN YOUR OWN DATA.

Instructions

1. Wear gloves to collect soil sediment. Break up clumps and remove any large pieces of debris.

2. Add egg yolk and carbonate source to mud, and stir to mix.

3. Pour 2 – 3 cm of the mixture into the bottle. (If using a plastic water bottle you can cut off the top part and invert to use as a funnel.)

4. Add the cellulose or starch to the mud in the bottle and stir, mixing the cellulose into the mud mixture. If using paper, shred into small pieces 2 -4 cm in length. The slurry should be about the consistency of a milkshake. Use about 1 paper towel per cup of mud.

5. Continue to add more mud mixture 2 – 3 cm at a time. (Mud mixture only, no cellulose or starch here.) Tamp down with each addition of mud to remove trapped air. Try to eliminate any air pockets in the layered mud.

6. When about 5 cm from the top of the bottle, stop adding mud. (You should have a minimum of about 12 cm of mud in the column.)

7. Pour 2 – 3 cm of water over the mud.

8. Seal the top with the cap or plastic wrap to prevent loss of water.

9. Wash your hands.

10. Place the bottle near a light source. If possible, place about 60 cm (2 feet) from a continuously lit light source of 40 – 60 watts. (If you use an incandescent bulb, you want to be sure that the bottle doesn’t get too hot.)

· Alternatively, you can place near a brightly lit window (although growth of photosynthetic bacteria will be slower).

· Do not place in direct sunlight (again, to prevent overheating). However, if outside temperature is 70 o F or higher, you can place column outside in the shade. (The column will begin to stink after a week or so, so outside is good.) Be sure that the shade is a bright shade, as the bacteria in the column require light for photosynthesis.

Data collection

Examine the column weekly for a minimum of eight weeks (ten weeks is better).

1. Take notes describing what you see each week and the changes that have occurred.

2. Take a picture each week so you have visual documentation of the changes.

Analysis

1. Try to identify the type of bacteria growing in your bottle at the various regions using the references below.

2. After identifying the bacteria, draw a schematic of a column. Identify areas on the schematic of chemoheterotrophic and photoautotrophic growth, and areas of anaerobic and aerobic growth in your bottle.

3. Show on your schematic the cycling of carbon and sulfur in the ecosystem of your bottle, identifying the chemical compounds in which they are cycled.

Conclusion

Refer to your hypothesis and in light of your analysis, compose a conclusion that addresses your hypothesis. If you did not observe what you expected, identify possible reasons that explain why. Explain what you might have done wrong or would do differently if you were to repeat the experiment.

Submit your report

Your report should include:

1. Title

2. The purpose

3. Your hypothesis

4. Methodology – a brief description of what you did in your own words (NOT a verbatim repeat of the instructions)

5. Data

a. Your weekly notes

b. A summary of the changes that have occurred over the time period that you have observed the column

c. Photos – minimally, beginning and ending photos

6. Analysis

a. Your identification of the types of bacteria growing at the various levels in your Winogradsky column

b. Your schematic diagram showing the ecological relationships in the bottle and the cycling of nutrients

7. Conclusion