However, we can appreciate so many differences between our bottle and the one in the light side, which was the column made by the group 11B.
As in our column, in here we can see H2S at
the bottom of the bottle, but in this case it has appeared another microorganisms that grew depending on
the light they were receiving.
In the side where the light strikes directly, microorganisms
with differents color have developed.
The dark violet patches are sign of the presence of the
sulfur bacteria. Next to them some iron oxidizing bacteria have grown. They are
orange and we think they are the same that were on the top of the column which
stayed in the dark side, even though we don´t know why they are there.
On the other hand, the side where the bottle wasn´t receiving
direct light, has an intense green
color, corresponding to the green sulfur bacteria.
On the top of the bottle we can see heterotrophic bacteria,
with a green and brown color.
The orange you see in the light column and the orange in the dark column are not the same. The first are light-dependent iron oxidisers and the second, in the dark, are iron oxides, probably in combination with sulfates, that precipitate (light does not play a role here).
ReplyDeleteThe green microorgaisms you see on the side are simply cyanobacteria. Green sulfur bacteria need a lot of sulfide and would not grow there. The same is true for the green "bacteria" on top. They are not heterotrophic bacteria but cyanobacteria or green algae.