Hello everyone!
We are a group of students of Biotechnology from the
University of Cadiz.
We made our Winogradsky on March, 4th. The column is
composed of some muddy sediment from an hypersaline lagoon, at which we added some
enrichment material in order to promote bacteria’s growth:
- Calcium sulphate (CaSO4) and ferrous sulphate (FeSO4): By adding these components we enhance the growth of sulphate-reducing bacteria, as they use sulphate as oxidant agent, reducing it to sulfide. Also these components provide Ca2+ and Fe2+ ions to the column.
- Sodium chloride (NaCl) in small quantities, which provides Na+ and Cl+ ions, necessary for bacteria's metabolism.
- Motor oil, as a source of carbon.
- Calcium sulphate (CaSO4) and ferrous sulphate (FeSO4): By adding these components we enhance the growth of sulphate-reducing bacteria, as they use sulphate as oxidant agent, reducing it to sulfide. Also these components provide Ca2+ and Fe2+ ions to the column.
- Sodium chloride (NaCl) in small quantities, which provides Na+ and Cl+ ions, necessary for bacteria's metabolism.
- Motor oil, as a source of carbon.
Firstly at the laboratory we placed our sediment in
a bucket and cleaned the sediment out of rubbish. Once cleaned, we added the
enrichment material and mixed with our hands. The mixture was then filled in a
1,5 L capacity bottle, filling about ½ of its capacity. Finally we added to the
bottle some water from the same lagoon, to fill about 2/3 of the bottle. The Winogradsky
column was ready to start the experiment!
The bottle was placed in the corner of a well-illuminated
courtyard, but not directly in the sun. One side of the bottle is always directed
toward the sunlight while the back, where the sunlight doesn’t reach, is
directed toward the walls. By this we’ll differentiate bacteria that use sunlight
to growth to those that don’t. Moreover, the bottle remained always uncovered,
so bacteria can obtain oxygen from the outside. This way we made a gradient of
oxygen inside the bottle, where bacteria that use oxygen will grow at the top
of the bottle (where oxygen is more abundant) and those that do not use oxygen will
grow at the bottom.
This is the appearance of the bottle the second day (March 5th). We can see the turbid water on the top of the column, and the sediment below. The back side of the bottle has exactly the same appearance.
Here is a top view of the bottle:
The first week we've not reported many changes: the sediment became darker, and in the third day some snails from the outside entered the bottle.
We'll keep posting the evolution of our column over the weeks. See you soon!
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