Mystery TSA Dish by Nathaniel Cutshall

The lab we did in class was on bacteria. As a part of this lab, we tested different surfaces around the lab room and EDCC campus. To test the bacteria content in these places, two petri dishes were taken, and divided into three sections, allowing for three different surface areas to be tested. One petri dish was then incubated at room temperature, and the other at 37 degrees Celsius; body temperature. The bacteria growth was then observed over the course of one week. The bacteria was observed on 4/4, 4/6, and 4/11.

For my surface samples, I picked the surface of the lab work bench, the outside of a fish tank in the biology lab, and finally I tested the forehead of one of my classmates. I tested the surface of the lab work bench because I hypothesized that since they are said to be regularly cleaned with disinfectant, there should be little to no bacteria growth from my surface sampled. I wanted to see if this was the case. I tested the outside of a fish tank because it looked dirty, which could mean there were bacteria. Finally, I tested the forehead of a classmate because skin is always warm and often moist, which would be a good surface for bacteria to live on.

Because April 4^th was when the bacteria samples were made, there was no growth observed on that day.

On April 6^th, bacteria cannot be seen on the room temperature incubation, but can be seen on the 37 degree Celsius incubation. The lab bench and the classmate’s forehead both have one small colony of growth. The outside of the fish tank can be seen to have two colonies of growth. The colonies were all composed of a crème color, and were spherical in shape.

The room temperature picture is on the top, and the body temperature on the bottom.

    

On April 11^th, growth can be observed on the room temperature petri dish samples. One small colony was seen for the outside of the fish tank, no colonies were seen on the lab bench sample, and 5 small colonies were seen on the sample of the forehead. The 37 degree Celsius incubation sample had significant bacterial growth. There was one colony of roughly the same size each in the lab bench and the forehead sample. The fish tank sample had increased to 3 colonies, creating almost a lawn of bacteria. These colonies had a ring around the outside and were crème color.

The room temperature picture is on the top, and the body temperature on the bottom.

Below is a picture of a microscope observation of bacteria from the outside of the fish tank on the 11^th of April.

In conclusion, I thought the patterns of bacteria growth were very interesting. The final product showed just as much bacteria growth on a forehead as there was on the lab bench. Because of the drastic difference in temperature and level of moisture between these two environments, I was surprised there was similar bacteria growth. In addition, all of the bacteria colonies that grew appeared to be the same, or at least very similar. This shows the diversity of climates that a bacteria can use as its host. This sampling of bacteria solidified the extreme adaptability of bacteria, and how they are almost everywhere.