You are a Biosphere
On October 31st and November 1st our Ap Biology class got the opportunity to go to U of R and peer into the world of microbiology (Microbiology is the study of microscopic organisms) during our time at U of R we were able to swab several objects including vending machines, doorhandles and even the inside of our mouths. After taking these samples we placed them on different agar plates. The plates we used were called Macconkey, Mannitol Salt And LB. The Macconkey and Mannitol Salt agar plates were selective from gram- and positive respectively.
Via scahealth.com
Top Left Macconkey
Top Right LB
Bottom Mannitol Salt
When we came back to U of R on November first we got to see the different bacterial growth on the different plates. The most visible spots of bacteria showed up on the Mannitol Salt and LB plates from the sample of a keyboard. There ended up being more visible bacteria on the keyboard than in my mouth or on any of my other samples. I wasn't expecting the keyboard to be perfectly clean but it was the same level of growth as some places in the washroom. Bacteria is all around us and more abundant than I first thought.
At the end of the lab we had a class discussion about the presence of Bacteria in the home and found that sponges are the most bacteria infested item in the average household. Sponges have an average of about 10 million bacteria per square inch. But there is something that each of these lists forgets about when considering the most bacteria per square inch, and thats you.
On the average person around 50 million bacteria per square inch can be found on the skin but on areas that are more oily like the face, up to 500 million bacteria per square inch can be found. It just gets worse from there; travelling inside the gut we can find upwards of 10 trillion bacterial cells. These bacterial cells actually outnumber our cells by about 3:1, but because of their smaller size they only make up about 2kg of our weight. These bacteria cells can affect us a lot in our day to day lives. It was recently discovered that our gut is lined with the same number of neurons as our spinal cord, this group of neurons is not just in charge of telling us when we are hungry but can also influence mood and stress levels without communicating with the main brain at all. All of the neurons are controlled by the bacteria, this raises some questions about who you are.