The unknown bacteria project consisted of a number of steps for identification. After receiving my assigned bacteria (HH), I began the identification process by creating a mixed culture plate.
The purpose of spreading the mixed culture on the petri dish of agar into four quadrants is to isolate the bacteria for identification. The goal is to achieve isolated colonies in quadrant four. It is important to separate the different species away from each other so they do not mix and become cross-contaminated. Colonies are significant and important to identification because they can be tested further for bacterial classification. Once obtaining a colony, I touched it with a sterile loop and streaked it onto another plate. This transfer or passage of microbes is described as subculturing. Pure cultures are needed, because an isolated species reacts differently than a mixed species. Thus, false positive or false negative results could be acquired. The relationship of all the bacteria on the subculture plate is that all of it derived from a single parent cell. After incubation, I discovered that my plate consisted of a pure culture. I came to this conclusion because all of the bacteria and colonies on the petri dish looked identical. …show more content…
The purpose of gram staining is to determine the makeup of the bacteria’s cell wall. This test also determines whether the bacteria is gram positive or gram negative. The thickness of the cell wall and its peptidoglycan makeup allows the bacteria to stain either purple or pink. A thick layer of peptidoglycan can retain the crystal violet color. The gram negative bacteria have a thinner layer, and the purple color is lost during the gram-staining process. I determined that the morphology of the bacteria was rod shaped by examining it at 1000x’s magnification under the microscope. This test provided the gram-negative rod characteristic to the unknown bacteria. The next step was the MacConkey
The purpose of spreading the mixed culture on the petri dish of agar into four quadrants is to isolate the bacteria for identification. The goal is to achieve isolated colonies in quadrant four. It is important to separate the different species away from each other so they do not mix and become cross-contaminated. Colonies are significant and important to identification because they can be tested further for bacterial classification. Once obtaining a colony, I touched it with a sterile loop and streaked it onto another plate. This transfer or passage of microbes is described as subculturing. Pure cultures are needed, because an isolated species reacts differently than a mixed species. Thus, false positive or false negative results could be acquired. The relationship of all the bacteria on the subculture plate is that all of it derived from a single parent cell. After incubation, I discovered that my plate consisted of a pure culture. I came to this conclusion because all of the bacteria and colonies on the petri dish looked identical. …show more content…
The purpose of gram staining is to determine the makeup of the bacteria’s cell wall. This test also determines whether the bacteria is gram positive or gram negative. The thickness of the cell wall and its peptidoglycan makeup allows the bacteria to stain either purple or pink. A thick layer of peptidoglycan can retain the crystal violet color. The gram negative bacteria have a thinner layer, and the purple color is lost during the gram-staining process. I determined that the morphology of the bacteria was rod shaped by examining it at 1000x’s magnification under the microscope. This test provided the gram-negative rod characteristic to the unknown bacteria. The next step was the MacConkey