Summary The purpose and goal of this project was to perform a number of tests in the lab and use a dichotomous key to eventually classify a Gram-positive cocci that we were given on March 25th. The key has seven tests to help you determine a certain bacteria, your tests will later on lead you down a certain side to contribute in defining the genus and species. All the following procedures were carried out on the gram positive cocci unknown in this order: Catalase, Oxidase, Nitrate Reduction, Oxidation-Fermentation, Phenol Red, Bacitracin, Coagulase, and lastly, Gelatin Hydrolysis. These tests led me to believe that unknown number 93 is Kocuria rosea.
Discussion
Looking at the dichotomous key, the first test that helps narrow down the bacteria …show more content…
Then make sure to label both of the tubes with your unknown number, name, date, and also the actual test that you are performing. Next, you will then inoculate each tube with your unknown aseptically with a flamed loop. After the tubes are incubated, you will read your results after a few days. My results led me to the left side of the key with oxidation results, green in the tube with the oil and then green with yellowish tint in the tube without oil. I ran into some troubles reading these results due to the fact that the tube without oil barely had any yellow growth leading to the difficulty of finding the result of oxidation. The next test, Bacitracin Susceptibility, was the next test on key that helped lead to the identification of the unknown. For this procedure, you grab a Blood Agar plate, and then streak the plate with a flamed loop containing your unknown. After the plate is streaked, you will then ask your instructor to place antibacterial discs throughout the plate. These antibacterial discs, after growth, will show the zone of inhibition which will then lead to your results. You leave the plates for a couple days in order to later on see some growth. My results were …show more content…
I measured 11mm which translated to being susceptible (sensitive to bacitracin). Due to this test, looking at the key I was still on the left side with it saying >10 and susceptible. Nitrate Reduction was the next test, which ended up being a very tricky one. This test had two periods, the first was identical to all the others. Obtain a tube, this one contained nitrate broth, label the tube and then aseptically inoculate the tube with the unknown bacteria. The second period after letting the broth incubate at 30 degrees Celsius, you add 12 drops of both nitrate reagent A & B. You then wait a few minutes and then read your results. If your results turn red, that would indicate that your bacteria is positive for nitrate and you stop testing. this is what my results turned out to be. After this test, I was pretty positive that I was certainly on the left side of the dichotomous key due to the left side saying positive for nitrate. The last test, Gelatin Hydrolysis, was the last test that helped identify my unknown bacteria. The procedure for this test is split into two as well. The first period you obtain tubes and label them, and then aseptically transfer the unknown into
Discussion
Looking at the dichotomous key, the first test that helps narrow down the bacteria …show more content…
Then make sure to label both of the tubes with your unknown number, name, date, and also the actual test that you are performing. Next, you will then inoculate each tube with your unknown aseptically with a flamed loop. After the tubes are incubated, you will read your results after a few days. My results led me to the left side of the key with oxidation results, green in the tube with the oil and then green with yellowish tint in the tube without oil. I ran into some troubles reading these results due to the fact that the tube without oil barely had any yellow growth leading to the difficulty of finding the result of oxidation. The next test, Bacitracin Susceptibility, was the next test on key that helped lead to the identification of the unknown. For this procedure, you grab a Blood Agar plate, and then streak the plate with a flamed loop containing your unknown. After the plate is streaked, you will then ask your instructor to place antibacterial discs throughout the plate. These antibacterial discs, after growth, will show the zone of inhibition which will then lead to your results. You leave the plates for a couple days in order to later on see some growth. My results were …show more content…
I measured 11mm which translated to being susceptible (sensitive to bacitracin). Due to this test, looking at the key I was still on the left side with it saying >10 and susceptible. Nitrate Reduction was the next test, which ended up being a very tricky one. This test had two periods, the first was identical to all the others. Obtain a tube, this one contained nitrate broth, label the tube and then aseptically inoculate the tube with the unknown bacteria. The second period after letting the broth incubate at 30 degrees Celsius, you add 12 drops of both nitrate reagent A & B. You then wait a few minutes and then read your results. If your results turn red, that would indicate that your bacteria is positive for nitrate and you stop testing. this is what my results turned out to be. After this test, I was pretty positive that I was certainly on the left side of the dichotomous key due to the left side saying positive for nitrate. The last test, Gelatin Hydrolysis, was the last test that helped identify my unknown bacteria. The procedure for this test is split into two as well. The first period you obtain tubes and label them, and then aseptically transfer the unknown into