Where did you obtain your soil sample?
I obtained my soil sample from Peeble’s Island which is near Waterford, New York. I live in Waterford and I go to Peeble’s Island all the time when I can. I went to the beginning of one of the trails on the island, and decided to go a couple feet away from the trail and collect my soil sample there. I collected the dirt in between a tree and many smaller plants. I collected the sample about 2 inches below the surface since there was a lot of leaf litter on the top layer.

Why did you choose this location?
Since Peeble’s Island is home to many different kinds of trees, plants, and wildlife, I thought it would have very rich soil. I was also curious to see what kind of bacteria I could find in a place that I had spent so much time walking around!

Do you expect a lot of isolates? Why or why not?
I expected a lot of isolates because I expected the soil to be rich since it supported such a wide variety and large amount of plants. The soil also seemed like it would get enough oxygen to support aerobic bacteria which is the kind we are growing in the lab.

Have you initial observations supported this?
My initial observations have supported this. I was only able to determine a cfu for one plate which was on PDA and a dilution of 1:10000. All of the other plates had way too many colonies to even count, even after incubating for only 48 hours. The 1:100 dilutions were completely covered with bacteria on all the different medias I used.

What media did you choose? How did you sample differ on the different media?
I chose LB, AC, and PDA for my media. Everybody had to use LB, but I wanted to use another rich media to see how many different bacteria I could grow. I realized that since my soil was likely rich, I would need to use the weakest dilutions on LB and AC since they would support the most growth. I knew I needed to use a minimal media, so I chose PDA as my third media. I noticed there were more potential antibiotic producers on the rich media compared to the minimal media, but there was significantly more diversity on the minimal media. The most common colors on the rich media were off-white and there was occasionally a yellow colony. On the strongest dilution of PDA most of the colonies were pretty small and close to white. On the weaker dilutions there were more colors including pure white, off-white, yellow, orange, purple, dark brown, and green. There’s also fuzzy bacteria (or potentially mold) growing on the PDA plates which hasn’t grown on the rich media plates.

What dilutions?
I plated the 10-2, 10-3, and 10-4 dilutions for all of the media since I guessed the 10-1 dilution would have too much bacteria in it.

Will you need to redo any?
I am redoing the 10-4 dilution on PDA since it was my most interesting plate. I am also plating a 10-5 dilution on LB and AC since I couldn’t get a cfu on any of those plates.