Blog Assignment #3: Mystery Microbes

Blog Assignment #3: Mystery Microbes

·         What objects did you decide to sample and why?

I decided to sample the lab table surface, under my shoe, hair, and the back of my phone. I chose the lab table surface because they tend to be washed after lab so I wanted to see if anything would still grow on them. I tested under my shoe because they’ve walked through so many things so there’s bound to be some interesting growth. I chose to test hair because a friend of mine tested it once and tan colonies grew however no one else tested hair so I am replicating her experiment. The back of my phone was tested because I was curious how contaminated it was after placing it on tables and handling my phone after touching other objects.

·         What type of growth did you see on Day 3? on Day 7? Describe the growth.

Day 3: Only under shoe has growth

Day 7: Large amount of growth under my shoe

On Day 3 the only growth I could see was under my shoe. There was a lot of growth and there seems to be multiple different colonies. A largest growth was white, dull, wrinkled, and filamentous. 5 colonies that were cloudy white, circular, raised, glistening, and moist. 8 colonies that were yellow-tan, circular, raised, glistening, and moist. 8 colonies were tiny white, circular, raised, glistening, and moist.

On Day 7 the filamentous bacteria grew over to the other sections. Before it was white in color but now it is yellow-brown. Because of the extreme growth I couldn’t quite see what the other sections had. But Hair had two visible yellow-tan circular colonies and there were four yellow-tan circular colonies under my phone.

·         Did you have growth from all the samples? If not, why do you think that happened?

Unfortunately because there was so much growth from under my shoe I couldn’t tell if the lab table had any. If not then the reason may be that we can only grow 1 % of bacteria in a lab. The conditions of the dish may not have been optimum for some bacteria and they would lay dormant.

·         What sample yielded the most growth of organisms? Why do you think that happened?

The sample under my shoe yielded the most growth. I think this happened because the petri dish contributed the best environment for this bacteria to grow.

·         Did anything about the growth you observed surprise you?

I expected some growth in everything I tested however I was surprised by the amount of growth that happened by the sample from under my shoe.

·         Describe the plate of your lab mate. What did you notice about their plate?

Day 7: Gretchen's petri dish

I compared my plate with Gretchen’s, she tested the bottom of her shoe, the focus knob of microscope #9, her cellphone screen, and the classroom blue dry erase marker. She had the same colonial growth as I did from the sample under our shoes. However hers did not grow as much as mine. From the microscope knob there are 5 yellow colonies. The cellphone screen had 2 yellow colonies.

·         Compare and contrast your plate with your lab mate's plate.

She and I both tested the bottom of our shoes. Comparing the two we both have the same types of bacteria that grew. We both had a lot of growth from that section however unlike mine, hers did not spread over to the other sections as much as mine. She and I also have the same yellow colonies that from our cell phones.

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

Microorganisms are so diverse that they can live in many different places and survive. Although we might not see some of them, they are still there and a live but lying dormant until the conditions of their environment is right.

·         Write at least 3 scientific questions based on your observation.

1.    In what other conditions would cause some of the 99% of microorganisms to grow in lab

2.    Could some of what grew in the petri dish be harmful?

3.    How does autoclave work and how effective is autoclave when the identity of the grown microorganism is unknown?

·         Write 1 hypothesis based on the questions above.

By changing conditions such as temperature, light, and medium, other microorganisms will grow.