Investigating Microorganisms Lab Report

914 Words 4 Pages
Title: Discovering Microorganisms Inside of the Lab and Out
Introduction: Microorganisms are everywhere, and they are usually associated with sickness or disease like E. Coli or Staphylococci. In reality, microorganisms help more than they harm. Microorganisms in our bodies help make everyday normal bodily functions possible. For example, normal microbiota found on the skin and gastrointestinal microbiota found in the digestive tract. If it was not present, it would make humans a lot more susceptible to harmful microorganisms. Without microorganisms, any disease would most likely happen more often and to more people. To learn more about microorganisms, in lab environmental samples were obtained. Throughout the semester characteristics of the
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The streak plate method is performed by streaking one quadrant of an agar plate then dragging the edge of that into the next avoiding contact with the previous quadrant again. This is continued until all four quadrants are complete, but it is important to not that the fourth quadrant never comes in contact with the first. This technique allows for isolated colonies. Obtaining isolated colonies is the first step in determining the microorganisms characteristics. The isolated colonies of the environmental isolate appeared white and were medium in size. In laboratory three, the different types of motility arrangements were presented and why true motility helped microorganisms in their environment. Motility agar was used in this experiment and a needle saturated with the unknown microorganism was inserted straight into the agar. The following week it was found that there was no bacterial growth outside of the stab line in the agar which indicates the unknown as being nonmotile. The unknown microorganisms morphology and the arrangement were identified after laboratory four through simple staining. Single staining consists of a single dye which informs only about cell shape and size, rather than differences between cell components. Through the simple stain, it was found that the unknown is a staphylococcus microorganism which is spherical and in clusters. The gram stain was performed in …show more content…
The environmental sample stayed purple suggesting that it is a Gram-positive organism. In laboratory ten selective, differential, selective and differential, and rich media were used. Mannitol Salt Agar is a selective and differential media which selects for Gram-positive bacteria and inhibits Gram-negative bacteria, therefore, it corresponds with the Gram stain indicating that it is indeed Gram-positive because the unknown grew on this plate. However, the media remained pink and did not turn yellow, which indicates that it does not ferment mannitol. The unknown did not grow on MacConkey Agar or Eosin Methylene Blue Agar because both of those select for Gram-negative bacteria which is consistent with the Gram stain. This gave some insight on what sugar this microorganism was able to metabolize, but in laboratory eleven, the phenol red experiment gave more information about what sugars it metabolizes and which it does not. The unknown does not ferment glucose as a result of the phenol red remaining red, meaning

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