WSU Geomicro 2017, where geo and micro nerds come together for the common good.
Winogradsky Columns... What are we testing? The combination of dirt, carbon, sulfur, and water. Oh, and some unintentional duck feces and twigs and such, and maybe some parts of construction workers made it in there too. So again, what are we testing with all this goodness? What microbes are going to grow and how growth differs based on the variables. Exciting ay? We think so.
What are the variables? Well, a handful of things. It used to be more than a handful of things, but then in the middle of the experiment it became apparent a few of the variables were not logical. So, here we are, with only a handful of variables and the oh-so-typical and necessary “controls.”
Controls, Variables, and Procedure
Conditions of mud sample site:
Air temperature: 30.5 C, 20% humidity, sunny, light breeze
Water temperature: 27 C, calm
DPM temperature: 30.9 C, full of sticks and leaves and fowl excrement
DP Water Retrieval
We used a blue bucket to scoop up duck pond water and poured it into a three-gallon water container and returned it to the lab.
DPM Retrieval
We began on the north side of the pond, Serena overcame her germaphobia to scrape the mud from the bottom of the pond for its sediment only to discover the pond is actually concrete... Pretty big kink in the plan, right? But no worries, eventually we found this plot of mud surrounded by ducks and geese who started coming at us—assuming we had food. We did not. Once they realized this they quickly deserted. So, with kitchen spoons, we dug up this mud which smelled of foul avian feces. We collected the mud in a blue bucket and carefully carried it back to the lab.
Mix Sediment Control
Procedure: An egg was smashed into a column. Equal amounts of DPM and CD were added to the 30% line, and the soils and egg were mixed together in a slurry. More soil was added to the 80% line. Then water from the Weber State duck pond was added to the 90% line. The column was covered with saran wrap secured with a rubber band, and the column was placed in the west-facing window of Tracy Hall lab 462.
Mix Darkness
Procedure: The column was set up in the same way as the mix control. The column’s sides were then covered in a black garbage sack and taped and rubber banded in place. The top of the column was left open to the sunlight from the west-facing window of Tracy Hall lab 462.
The Column of Greatest Importance
Now that we have the basic rundown of this entire Winogradsky experiment, let’s narrow this down to which column we (Emily and Serena—the authors of this wicked good blog post) are going to be observing over the course of the semester.
We chose to observe and track the progress of growth on the “Mix Darkness” column, compared to its control “Mix Sediment.”
Week One:
1 2 3 4
These pictures were taken at about 1:00 pm, Thursday, September 14, 2017. The garbage sack around the dark column was carefully removed and pictures 1 (side facing the window) and 2 (side not facing the window) were taken. The control was merely turned to get shots of the sunlit side (4) and the side that does not face the window (3).
We hypothesize that the garbage sack will affect growth due to the lack of sunlight as well as the insulation. The bag will make the column temperature slightly warmer as well as dark. The diversity of growth, we believe, will consist of microbes that hate UV light and microbes which are facultative when it comes to UV light, resulting in a greater visible diversity than the control, which is exposed to light all the way around the column.
That's all for this week, folks! Stay tuned!
--Serena and Emily
