12.15.14: Happy Birthday, Mom! I got you a jar of DIRT!

It's my mom's birthday, and I'm spending it observing my column during its last week, before I have to tear it apart into separate layers.

I did notice some slightly different changes this time around.

In Column #1, I always feel like the water layer is constantly shifting from the middle of the column to the top of the column, then back to the middle again. I'm not sure why it's divided this way, instead of just having the water sit on the top of the mud (similar to how it was when I first set up this column).

I hypothesize that the presence of methane-producing bacteria is responsible for the pores, the gas bubbles in the pore, and the rearrangement of the water layer to the middle of the column.

My other hypothesis is that the bacteria below the water column are different that the type above the water column--that they feed on something else, and that is the cause of the division between the two mud layers.

I THINK I FINALLY FOUND AN EXPLANATION FOR THE THE "SCUM LAYER" ON TOP OF THE WATER LAYER IN COLUMN #2!!!

We talked about BIOFILM in class (Lecture #18 perhaps?), in regards to bacteria deciding whether or not they want to "swim" (keep their flagella) or produce BIOFILM.

I looked again at one of the sources that I used for the instructions to build my column in the first place, and it said this:

"The water column at the surface is in contact with the atmosphere and is therefore aerobic but it becomes increasingly anaerobic with depth. The surface layer of the column may produce an aerobic liquid air biofilm (pellicle) that can be sampled by dipping a coverslip into the column and lifting a portion of the film from the water." 
<http://www.personal.psu.edu/faculty/j/e/jel5/biofilms/winogradsky.html>

When I take apart my column, I will lift a portion of the film from the water to look at it.
I want to observe it on cellophane, but if I get the chance, I would love to borrow a microscope to look at it more closely (if time permits).

There are slightly less gas bubbles this time around, but the orange pigment in the biofilm is still as vibrant, and the greenish-brownish portion of the biofilm is clinging to the edges of the column!