Microorganisms Everywhere Lab Report

Title: Microorganisms are everywhere.
Tara Brady
Dt201
Objectives:
In this experiment, my aim is to prove that microorganisms are present everywhere and that nowhere in our everyday lives is free from bacteria. I expect this to be the case as even germicide soaps do not kill all bacteria present on our skin; likewise household cleaning products are incapable of killing all microorganisms present. I am doing his experiment to verify the concept that microorganisms are everywhere and I most certainly expect my results to prove so. I expect to find many shapes, sizes, colours and indeed types of microorganisms present when I observe the morphology of the colonies present.
Materials and methods:
Swabs.
Diluent 0.1% peptone.
TSA (Trypticase
soy agar) plate.
SDA (Sabouraud agar) plate.
Note: I used one side of each to place a sample from the environment and the other side of each to place a sample from my body.

1. I carried out aseptic technique this involved wiping down my area of the bench using disinfectant. I then set up the Bunsen burner within this area. I opened the packet of the sterilised swab took it out of the packet, I placed the lid of the diluent 0.1% peptone in the palm of the hand carrying the swab and I held the diluent 0.1% peptone in the other hand I rolled the rim of the bottle of it in the blue flame of the Bunsen to disinfect it, dipped the swab in it, and then quickly placed the swab back in its packet and rerolled the rim of the diluent 0.1% peptone in the flame again and promptly reapplied the lid.
2. To take the swabs from the environment, I removed he swabs from their packets and swabbed the floor of the lab and put them back in their packets. To take the swabs from myself, I removed he swabs from their packets and swabbed the inside of my cheek and put them back in their packets.

3. I then lifted the lid of the TSA plate slightly at an angle to prevent airborne microorganisms from contaminating the agar and smeared the surface of the agar with the swab from the floor and labelled it ‘TSA floor’. I did the same for the swab from my cheek and labelled it ‘TSA cheek’. I repeated this process for the SDA
plate.

4. I closed the plates immediately after I smeared them with the samples to prevent contamination.

5. The TSA plates were incubated at 37 degrees Celsius and the SDA plates were incubated a 30 degrees Celsius for 7 days to allow time for the growth of microorganisms. 6. I then disinfected my desk again.

7. On returning to the laboratory the following week, I carried out a macroscopic examination of the colonies present on both the TSA and SDA plates.

8. I recorded my results.

Results:
TSA plates:
During a macroscopic examination of the plate, on the environmental side I found many colonies. There were round, yellow, shiny, medium sized colonies; round, white, shiny, medium sized colonies and rod shaped matte white, large colonies. On the side containing the sample from my body there were also many colonies. There were punctiform, matte white, smooth colonies and round pale yellow, wrinkled, small colonies.

SDA plates:
On examination of the SDA plates I found further colonies. On the environmental side I found round, orange, medium sized, shiny colonies; white irregularly shaped, large colonies with a wrinkled surface; tiny, round, yellow, shiny colonies and rod shaped, white, medium colonies with wrinkled surfaces. On the side containing my cheek sample I did not find as many colonies as I found from the TSA cheek sample. There were a small amount of punctiform, white colonies.

Diagram of results:
TSA:

SDA:

Discussion:
From my results I feel that I have proven that microorganisms are everywhere, from the bottom of the ocean to the top of the world’s highest mountains.
There is also a lot of variation among microorganisms. I found many different shapes, sizes, colours and indeed colonies of microorganisms. This means that microorganisms are abundant in our everyday lives. They exist on absolutely everything; I found them on the floor and inside my cheek. As I previously thought, upon macroscopic examination, there was more bacterial growth on the floor than inside my mouth, although I did expect to find some more variation in my mouth as there were only colonies of the same kind present. There was much more variation in the types of microorganisms present on the floor samples. Perhaps this could have been due to the fact that some bacteria do not grow on artificial media. I feel that if I had of used different types of agar plates that were the favoured media for bacterial growth in the mouth, I could have found more bacteria present. Another reason for the small amount of growth could have been due to experimental error when obtaining the samples with the swabs. I could have swabbed with one side on the swab and smeared the other side of the swab on the agar plate which would not have come into contact with the area to be examined such as the floor. From my results I gather that some microorganisms favour certain agar plates, for example I only found yeast growth on the SDA plates as this
plate is generally used for the growth of fungi. In summary, microorganisms are found everywhere, they are found in some places more than others, and for example water fountains often contain more microorganisms, particularly bacteria, than toilet water (abc news). Also, microorganisms are a huge part of our everyday lives and tend to grow rapidly in optimum conditions, for example on a nutrient rich agar plate, kept for a week at the correct temperature. To conclude, I have learned how to determine microbial abundance and prove that microorganisms exist everywhere.
References:
http://en.wikipedia.org/wiki/Growth_medium http://abcnews.go.com/GMA/story?id=3293080&page=1 http://www.encyclopedia.com/topic/bacteria.aspx