UCA_5A_6A_7A: Day 88 Finishing the project

Hi everyone,

This should be our last report about our Winogradsky Columns. As you will see now, the three columns have remarkable changes since we put our last entry.

Evolution of Winogradsky Columns

Group 5A: The red part that was observed in our second entry has moved, and now, it takes a place in the solid part. Now, we found two different zones with two different colors. In the red zone, we can find bacterias that affix nitrogen and in the black zone, bacterias that affix sulfur. Both are anaerobic, however, for those bacterias who affix nitrogen, the toxicity that is caused by O2 is less dangerous. All in all, we conclude what we already thought before, our entire column is anaerobic, but there are two tonalities, which is not what we used to think, since our conclusion was that there would only be one color.

Winogradsky Column 5A group:

 

Group 6A: After three months we see that the column has change a lot, being almost black except in the lower part, that is due to the precipitation of elemental sulfur as a result of the metabolism of the sulfur bacteria that oxidize the H2S to S. Also there are many points which are bubbles of H2S. The black zone is produced by anaerobic breath with sulfate, that produce H2S which precipitate with Fe producing FeS.

Winogradsky Column 6A group:

Group 7A: Our column has changed a lot during this time. First of all, we have seen the appearance of algae and cyanobacteria. This match with our column, because we left it in a light environment. Also, we have noticed that the orange colour in the middle part has increased, this is produced by photoheteroorganotrophic bacteria. We had black colour in the bottom of our column, but in this case it has extended through the column, but it stops in the middle part. This colour is produced because anaerobic respiration with sulfate was produced. Anaerobic bacteria produce hydrogen sulfide (H2S), that with the Fe, they precipitate in a abiotic way creating FeS. This compound makes the black colour in the column. Finally, we still have gas bubbles through the column, probably CO2 and H2S.

Winogradsky Column 7A group:

After all, we have seen the evolution that a Winogradsky Column may have through a period of time. However, it may increase or appear other organism through the column during this time.

I hope everyone enjoy our entry as we enjoyed doing it. 

 

Thanks everyone and keep follow the activity of this amazing blog.