My Winogradsky Protocol

For my Winogradsky expiriment, I am trying out two different protocol. I have used four 1 litter water bottles - two using a protocal from the NASA site - Chain or web? grow chemosynthetic bacteria - which can be found at: www.bigelow.org/foodweb/chian4.html. This protocol is primarily concerned with whether or not photosynthesis is the only way to make food. This experiment is meant to show how bacteria will oxidize hydrogen sulfide to produce carbohydrates without any sunlight involved. I like this version because it is set up as a lesson plan for teachers. There are learning objectives, procedures, and extension activities. I was not thrilled about the procedure section though because I found it a little difficult to follow having never done one of these before. I also substituted the call for Plaster of Paris (CaSO4) with magnesium sulfate, which I am assuming will work out ok.

For both protocols I collected mud and creek water from Bear Creek in downtown Merced. I was relieved to find that there was enough water still in the creek to collect this late in the year (we haven't had rain for a long time and probably won't until the beginning of November).


For the first protocol, I combined about 4 grams of magnesium sulfate with enough mud from the creek to fill the first 1/3 of my water bottles. I stirred it in a container and then mixed it with filter paper strips. The procedure calls for lab filter paper, which I substituted with coffee filter paper - again, I'm not too sure how well this substitution will work out. I transferred the mud mixture to the water bottles and added the creek water. Then added .2 grams of baking soda and one crushed multivitamin pill. I attempted to remove air bubbles, but I did not feel highly successful in doing so. I let the bottles sit for about 30 minutes and then poured off a little bit of water and covered with plastic wrap and a rubber band. I marked one to sit in sunlight and one to be closed in a box.


For the second protocol I used the instructions from one of the links provided: http://www.personal.psu.edu/faculty/j/e/jel5/biofilms/winogradsky.html, which was apparently created by a Penn State faculty member. I think this protocol is a more traditional source of directions on the Winogradsky Column. For this protocol I used the same mud and creek water and also mixed the mud with magnesium sulfide. However, for the carbon source, I used one of the other recommendations - cut grass. These instructions do not include the use of baking soda or vitamins. I marked both of these bottles as well for one in sunlight and one in the closed box.

Here are the bottles right after mixing, prior to settling as well as a top down image:







The bottles looked like this last night in my window, I think it's clear that I missed the boat somewhere and didn't use enough mud. I'm not sure how that will affect the experiment overall or if I will have to start over:

The chemosynthetic bacteria site was very specific about putting the bottles right away in their dark box, so I didn't take pictures of those bottles (they looked the same - as you see above, the one on the right that is more "yellow" has the baking soda and vitamins added. I packaged my dark bottles in a box and covered them with a dark plastic bag - I'm leaving the box on my kitchen counter because it asks for the conditions to be the same. It gives a good recommendation about viewing them with a red light on a weekly basis, so I'm going to try that:

A couple of other great sites are:
http://people.clemson.edu/~skipper/In%20progress/winogradsky/winogradsky.htm
http://www.sumanasinc.com/webcontent/animations/content/winogradsky.html