12.19.14: THE BIG FINISH!

The time has come to finally disassemble my columns!!!

***NOTE***
I had to transport my columns to my boyfriend's house STRAIGHT after my last finals due to complications in his schedule. While I planned to take it apart yesterday, time didn't permit it. This is important because my columns shifted during the car ride to Cincinnati. My biofilm layer in Column #2 completely disappeared, as a result, so there was no biofilm layer I could observe when I broke down my columns.

Materials for Breakdown:

1. Cellophane
2. Plastic Spoons

Column #1

When I removed the cellophane on top of Column #1, it smelled earthy and compost-like, but it smelled like that in a "bad way."

Also, I was surprised to find that there was mold growing on top of the biofilm!  

There is a lot of white, fuzzy mold on top of my column, and the top mud of my column appears green-ish in color. Perhaps this is the presence of green sulfur-reducing bacteria? Because this column was pretty much all anaerobic, this could explain its appearance in the uppermost part of the column.

Here we can see specks of orange underneath and around the mold and biofilm. 

Here are mud samples taken from the top of the column, the middle of the column, and the bottom of the column. There wasn't much visible distinction between the bottom and middle layer, but I did note that the mud there was slightly darker than the mud in the top layer.

When I finished sampling the mud out of the column with a plastic spoon, I noticed that the column was producing a lot of has bubbles on top of the mud that was left in the column. This must be because Column had no gas exchange with oxygen occurring, and once it was finally exposed to oxygen (I did this outside), gas exchange abruptly started to occur. Here's a video of it:

Column #2

Because the biofilm in Column #2 was disrupted during the car ride to Cincinnati, Column #2 was a lot less exciting to observe.

Gas exchange occurred all the time because the cap was left off of Column #2. No mold grew here, so it is possible that higher levels of oxygen inhibit mold growth.

The mud in Column #2 was pretty uniform throughout: one shade of green-brown.

I really wished the biofilm was still there. It would have been neat to spoon out and look at more closely. In case you forgot how cool and gnarly it looked, here's a refresher:

...I REALLY wish I could have looked at this when I took the column apart! -sulks-

Overall, it was a fun ride, little Winogradsky column o' mine. I learned a lot about lake and pond habitats and about why the types of bacteria grow in the places they do. I really wish it could have gone longer under more preferable conditions, like: NOT in winter (more sunlight), for a longer period (to permit more growth and separation of bacterial zones), and less uncontrolled but inevitable disturbance (Winogradsky columns DO NOT like car rides).

Warmest Regards,

Michelle Rabara

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!

12.13.14: Watching paint dry

I feel like NOTHING has changed in both columns.

I can't even make any new observations because nothing has [seemed to have] changed. 

Column #1:

Column #2:

I think MAYBE the mud level is a bit higher in column #2? If so, it's not by much:

This makes the layer of scum above the water easier to see:

Another aerial view of the scum layer in Column #2
Compared to the photos of this that I had taken previously, I guess the arrangement of gas bubbles may have changed, as some may have gone and some may have formed in a slightly different place.
I still think that the different patches of color on the scum is beautiful.

Browns and oranges and empty spaces inbetween...I think it's really pretty, and it's probably evidence that different bacteria a colonizing this scum layer. I'm sure that methanogens may still be present because the gas bubbles still exist (assuming the gas inside is methane). 

12.11.14: Why is nothing else happening?

I feel like the most exciting days of this Winogradsky column were near the beginning.
For the past week, my column has literally looked the same.

Column #1:

The mud didn't rise any higher.
The mud is still slightly orange-tinged below the red rubber band (which was speculated to be bacteria).
There is still a water layer/gab between two mud layers, more near the top of the column
There are still black-tinged spots near the bottom of the column by the gas bubbles.

Column #2:

The mud levels in column #2 never rose quite as high as they did in column #1. 

This may be due to the presence of oxygen, making it an aerobic process. I see a noticeable difference in number of gas bubbles as well, which are lesser in column #2

As a general note, there is a noticeable scum layer in column #2, but not in column #1.

Why did my water in column #2 get so turbid?

That's funny: there is still a lot of twigs and earthy plant matter in column #2. Here it is sticking out:

Ugh! Look at that scum layer resting on top of the water: 

Aerial view of the gas-bubbly scum layer, riddled with swirls and patches of copper-orange pigment.

12.9.14: An Aerial Look at Column #2's Scum Layer

The columns look the same as they did on 12.7.14, minus some minimal changes
However, I think the scum layer on Column #2 looks very interesting lately. An aerial view was taken for Column #2, but not for Column #1 (the condensation on the cellophane makes everything beneath it hard to see).

First, let's look at the notable (lack of) changes in Column #1:

I think the water layer actually dropped in level...or maybe I accidentally took the picture from a different side this time. Anyway, not much occurred besides some minimal mud-shifting. There is still some orange tinge at the top of the mud.

See the orange? And look at those gas bubbles in the pores of the mud! Wow.

Column #2 doesn't appear to have made any changes either, but here it is:

The mud levels look the same as they did two days ago, but the "scum" layer looks noticeably thicker.

See the light, frothy scum layer on top of the water layer?

Here is an aerial view of Column #2 The scum layer seems to have 2-4 noticeable gas bubbles and some discoloration. I see patches of a copper, orange-like brown color in different spots. 

12.7.14: No more changes in column

I feel like there are no more changes going on in my column...which is pretty boring.

The color is relatively the same in both columns.

Column#1:
The water segment in this photo rose to nearly the top of the column.
The mud is still porous, and the water and air pockets are almost all gone.
The cellophane is no longer bulging, so there are no more signs of gas production.

There seem to be spots that are tinges of green near the bottom of the column. I think these are green bacteria of some sort.

 Upclose view of the risen water segment:
There are spots near the top of the column that are tinted orange. Could these be new bacteria?

 Aerial view of Column #1:

Column #2:

I don't see much change in Column two, except for:

1. The mud level rose
2. The "black spots" near the top of the water level are now gone.
3. There is a scum layer on top of the water layer

One thing I have noticed between the two columns is that the mud in Column #2 is not as porous.

I also can't see any black-tinged spots in any region of Column #2.

Column #2 is exposed to oxygen because it's cap is off, so gas exchange occurs here