Phew!!! (and more!)

March 28th — An update on Column C (Thames Mud + Tap Water). It is later in the day post-unfortunate accident, and things look promising. The biofilm that stayed on the surface is as it was (fig. 1), and I've been able to see new growth on the surface. Looks like the microbes are going to make a stand!

Fig. 1 Here you can see the portion that is still on the surface of the water. The blurry stuff around it is the microbial growth on the surface.

While I've been worrying over the biofilm, I took a closer look at what else was going on with the columns. As before (and could be seen in the post "Oops!") Columns A (Potting Soil + Tap Water) and B (Potting Soil +Thames Water) showed no change. I did notice some things with Columns C and D (Thames Mud + Thames Water). First, there's a green ring around the surface of the water in Column C (fig. 2). Perhaps this is residue from the collapsed biofilm. The water also seems to be a bit daker than before, possibly because of the stirring up of the water, or maybe microbes that are able are "jumping ship" from the drowned portion of the biofilm.

Fig. 2 A green ring around the surface of the water in Column C. Also notice the tan color of the water. The dark brown in the water below the green ring is the half of the biofilm that is suspended in the water.

Second, I took a closer look at the side of the column facing the window and there are lots of orange patches in the mud! (fig. 3). I guess I've been so preoccupied with the biofilm that I failed to examine the mud closely, however I don't remember seeing any orange patches when I checked the columns on March 14th. This is the side of the column that gets the most sun. I wonder if I rotated the columns if I'd see orange growth all around, or would the microbes on the side facing away from the window die out? Also, I find it interesting that the dark ring that was found where the mud met the water has now largely disapated. There are some black specks on the wall of the column above the mud, but nothing like what it was before.

Fig. 3 Orange growth! Orange growth!! (Also notice the absence of the black ring that had previously been seen where the mud met the water).

Also, I wonder why Column C is so much more productive than any of the other columns? My initial prediction was that Column D, with the Thames Mud AND Thames Water, would have been the most productive, but it has not produced anywhere near the amount of biofilm that Column C produced. Maybe having tap/distilled(ish) water promotes the growth of the microbes better than the slightly saline water found in the river. I'll look for more info about that. Speaking of Column D, here's a good picture of the black particles right above the mud line (fig. 4). It's interesting that the moving of the columns did not seem to affect Column D as it did Column C. The growth on the side of the bottle seems to be doing just fine. Also, there is some orange growth in the mud in Column D too (yay!), though not as much as see in Column C.

Fig. 4 The black colored growth on the sides of the walls of Column D , just above the mud line. Also notice the orange growth in the mud. (For this picture, to best show the black growth, I rotated the column, which is why the orange in the mud is facing away from the window. I later rotated it back to the way it was.)