Winoblog, First post, group B7.

          In this post, we are going to explain our theories about the experiment that we have done in microbiology. This experiment is called “Winogradsky column”, his name came from first scientist that realized it.

           

           Our column was filled up with portions of natural mud, sand, and sea water. These are the column’s principal elements, but we need to add more nutrients for bacterial growth.   We need to create an oxygen gradient. In the bottom of the column there aren’t any oxygen (only sulphates SO₄^2-), and in the top the oxygen concentration is equal to the atmospheric.

         In order to create this gradient, we putted several nutrients to feed diferent kinds of bacterias. It is use to occasion a microecosystem where there are many food chains.

The nutrients we added were:

• -FeSO₄ (to give a sulphate source, and a iron source).
• -Cellulose (to give a source of carbohydrates that some kind of bacterias can use).
• -NaCl  (to equilibrate column’s osmotic pressure).
• -CaSO₄, Chalk (in order to give a calcium and sulphate source).
• -Yeast extract (it is use to nutrient source).

          Amount nutrients can change according to microorganism’s needs. It preferably utilize a low concentation of those because our Winogradsky column can take a long time to flourish o it can lead to methane wall cavities.

Figure 1: Methane wall cavities.

Figure 2: Winogradsky column. Photo taken after one week.