UCA_GroupA2_Day21

It has been three weeks since we prepared our column.

All the colours have been intensified and we can also distinguish the three parts that we could appreciate the last week.

At the top of the column, there are more algae than the last week.The reason why the algae have grown is due to the sun which provides energy for the photosynthesis. In this part, there are also growing aerobic microorganisms that produce oxygen and organic substrates thanks to the process mentioned previously.

In the middle we can see that the color has turned into light brown.The red regions have become bigger than the last week and we know that this is an indicative of purple non-sulfur bacteria.

At the bottom of the column, there are growing anaerobic bacteria. Above this microorganisms there are sulfur-reducing bacteria who will use sulfate for their anaerobic respiration and they also reduce the sulfate to hydrogen sulfide. When the hydrogen sulfide is combined with iron(II) sulfide, the black colour can be appreciated.

(we forgot to take photos )