This lab was conducted to test the effects of garlic when exposed to two different strains of bacteria. Garlic has been used throughout many centuries to treat common ailments from seasickness to intestinal parasites (Ankri and Mirelman, 1999). With the information gathered from this lab, we can conclude whether or not our predecessors were on the right track with this natural remedy.
Another reason for doing this experiment is to observe how natural antibiotics affect modern bacteria. With our modern medicine, people are diagnosed with a sickness and are given an antibiotic to ward it off. The patient is warned to take the entire contents of the medicine to ensure that all ...view middle of the document...
Then, there are the gram negative bacteria like the bacteria that we used in this experiment. They not only have a peptidoglycan layer, but also an outer membrane composed of a lipopolysaccharide. These bacteria are often more dangerous to our immune system because they are camouflaged and have a harder time being discovered. My group predicted that if S. marcenscens is exposed to crushed garlic soaked filter paper, then the growth of the bacteria would be inhibited more than it would be with the rinsed garlic or water filter papers because it would contain a higher potency of the chemical released from the breaking down of the garlic’s cell walls.
To conduct this experiment, the first thing we had to do was collect our materials. Our instructor had previously prepared our petri dishes by sterilizing them and filling them with agar, the food source for our bacteria (Gibson, 2014). We then needed a sterile cotton swab, a vial of S. marcenscens, two cloves of garlic, eighteen sterile circles of filter paper, two glass bowls, tweezers, a garlic press, a stirring rod, a graduated cylinder, a timer, an incubator, a sharpie, a ruler, tape, and our instruction manual (Vodopich, 2014). We used the cotton swab to dip into the vial of S. marcenscens and then transfer a thin layer of the bacteria over the agar. We divided the petri dishes into three regions labeled C, R, and W. They stood for crushed, rinsed, and water (Fig. 1). We then determined that we would soak each variation in 5 ml of water for one minute apiece. First, we soaked our filter papers in 5 ml of water and timed it for one minute using a phone. Then, we used the tweezers to place the one of the six circles in the appropriate section of each petri dish. Then we emptied the glass bowl and started the rinsed garlic. We placed a whole clove in the dish and poured the 5 ml of water over it while using the stirring rod to evenly mix the solution. Next, we placed in the filter paper circles and allowed them to soak for one minute. We used the tweezers to place each of the filter papers in the correct region of the petri dish. Finally, we crushed the garlic using the garlic press and emptied the contents into the glass bowl. We covered it in 5 ml of water while using the stirring rod to mix and then allowed the filter papers to soak for one minute. We transferred the last of the papers to the petri dishes and sealed the containers. The last thing we did was tape our six dishes together to incubate. We allowed them to incubate for five days. We then measured the rings of inhibition using a ruler and recorded our results in millimeters.
When we finished measuring our results, we found that they were very conclusive. We measured each diameter of the zone of inhibition. Then we recorded the data to make a bar graph bar graph so that we could view our data more conveniently (Table 1).
Each petri dish was relatively similar looking. The largest zone of inhibition was...