BIOL213 | PLANT BIOLOGY | SPRING 2017

Megan Thees

4/14/17

Mystery Microbes Blog #3

The objects I chose to test for bacteria were my cell phone screen, the cell phone cover, one of my rings that I wear on my ring finger and one of the light switches in the lab room. 

DAY 3:

As you can see from these pictures, there is little to no growth on day 3. I saw no difference between day 1 and day 3. There was no growth from any sample on day 3. 

DAY 7:

On day 7, there was definite growth from the light switch and from my ring. Still no growth from my cell phone screen or cover. From the light switch there are 4 dots of bacterial growth ranging in color from white, to cream, to a yellow brown all about the same diameter in size. The growth from my ring is a little different. There are more colonies, 6 bigger colonies about the same size in diameter, mostly a creamy brown color and then 3 smaller colonies about the same diameter to each other and similar cream color. 

I did not have growth from all samples. I was very surprised that my phone did not have any growth. I thought it would be interesting to see the difference between the screen and the cover because the cover gets set down in places and the screen gets touched by my fingers and face. I thought my phone would be very dirty because I rarely clean it. I do remember wiping it with Lysol spray within the last month so maybe there is some antibacterial residue left on there that isn't allowing bacteria to grow on it. Another reason there could be no growth for my cell phone is that only 1% of bacteria can be grown in the lab, so maybe the bacteria that is on my phone can't be cultivated in the lab. 

My ring yielded the most growth of organisms. Although I do wash my hands often because I work in the health care industry I guess it makes sense, especially with this particular ring because it has grooves in it where things can get stuck in there. I also don't ever take this ring off so things can get stuck under it, I guess. 

As I mentioned before I was surprised that my cell phone didn't have more growth because I thought that would be dirtier than my ring. Because at least my ring showers with me and washes my hands with me on a very regular basis! 

COMPARE:

Gretchen Janes Mystery Microbe Tray 

This is my lab mate Gretchen's plate. She tested the bottom of her shoe, microscope #9's focus knob, the blue dry erase marker and her cell phone screen. She had very little growth on her cell phone screen but more than my cell phone screen. This growth was represented as one larger colony and a tiny colony of yellowish color. There was a little bit more growth on the microscope knob then on her cell phone, similar colony structure with one bigger yellowish colony and 5 tiny dot colonies and then it looks to be a cloudy white colony similar in size to the bigger one. There was no growth on the blue dry erase marker. The most impressive growth and also the most disgusting was the growth from the bottom of her shoe, there was so much growth that the different colonies are indistinguishable. In fact there was so much growth that it over grew onto the microscope know section. 

Our plates were similar in that we got varying amounts of growth for the different things we tested. We both tested our cell phone screens but she had more growth on hers then on mine. The bacterial growth shapes and sizes were similar for my ring and light switch and her phone and microscope knob. Where as the shoe growth was a different breed of monster! 

Reflection: What does this mini experiment reveal to you about the ubiquity of microorganisms?

This experiment shows that microorganisms are everywhere, sometimes where we least expect them and sometimes more than we would like to know. It also shows that they aren't all bad because if the monstrosity of bacteria that grew from Gretchen's shoe is only 1% of what really out there, it obviously hasn't killed us yet. I thought this experiment would gross me out but the objects I tested were cleaner than I expected so it wasn't that bad, 

QUESTIONS:

• What type of bacteria are these? 
• What makes the growth more uniform circles vs. non-uniform blobs
• If only 1% of the bacteria from the bottom of Gretchen's shoe is present, should she wear her shoes into her house?  
• What do the different colors of growth mean?
• How long does the affect of disinfectant spray last before bacteria can grow again? 

Hypothesis: 

If bacteria are exposed to Lysol disinfectant spray, then the population of bacteria will decrease.