Essay On Nitrate Test

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During the phase and process of the bacterial unknown project, vast amounts of test were performed in order to determine an unknown species of bacteria. Within the many procedures of identifying the unknown bacteria, I was first given a tube with the unknown bacteria, from which later on I started subcultures by streaking bacteria from the original tube onto a tryptic soy agar (TSA) slant. Throughout the process of identifying the unknown, new subcultures were produced in order to use the newest bacteria to conduct the tests. Thus, this process allowed the unknown bacteria to grow and maintain. Before a series of test were conducted, first a gram stain test was performed in order to determine the unknown’s gram reaction and its cell morphology. After the gram stain procedure the unknown bacteria appeared purple and roughly spherical, when seen through the microscope. Thus, this concluded that the unknown bacterium was gram positive and its cell morphology was cocci. After this, a series of test were conducted in order to identify the unknown.
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The nitrate test was conducted in order to see if nitrate was present. After the addition of two percent acetic acid the unknown had no color change (negative) and therefore the test could not be used for Pseudomonas species. In order to see if the unknown could use citrate as its sole source of carbon, a citrate test was performed. The media of the citrate test contained bromothymol blue, a pH indicator that would have turned blue if the if the organism had a positive reaction. However, my unknown remained green, the original color of the slant and had no growth of the bacteria. The unknown was also unable to utilize malonate as the sole source of carbon. Once the malonate test was done, there was a yellow color, which indicated that it was

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