Types Of Gram Negative Bacteria Essay

1706 Words Nov 9th, 2015 7 Pages
The reason for conducting this experiment was to determine and identify a given unknown bacteria and to understand how to recognize the variance between the several types of Gram-negative bacteria. The given Gram-negative bacteria would be classified as one of the following microorganisms: Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa or Salmonella typhimurium. To confirm the Gram-negative properties of the bacteria a Gram Stain procedure was carried out and to distinguish our given unknown from the remaining five bacteria, a variety of thoroughly run tests were conducted to ensure accuracy and precision. A T Streak plate was created from the unknown bacteria and then used in the following biochemical tests: Methyl Red test, Voges-Proskauer test, Triple Sugar Iron Agar test, Urea Hydrolysis test, Sulfur Indole Motility test, Citrate test and the Gelatin Hydrolysis test. After the completion of these tests and adequate incubation time, the results of the tests were observed and the number fourteen Gram-negative unknown bacteria were identified as E. aerogenes.
II. Introduction
A Gram stain is a differential stain, as the name implies, a differential stain permits microbiologists to discover differences between organisms (Leboffe & Pierce, 195). A Gram stain not only distinguishes between positive and negative but it also gives reputable classification in morphology, size and arrangement. Gram- negative bacteria…

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