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Microbiology

The Long Awaited Answer to my Unknown

Johnny Tran
August 2, 2006
BIOL 3444-002
Unknown #12

Introduction
Bacteria are microscopic unicellular prokaryotic organisms characterized by the lack of a membrane-bound nucleus and membrane-bound organelles. They are remarkably adaptable to diverse environmental conditions and are found in bodies of all living organisms and on all parts of the earth. The purpose of microbial biochemical tests is to identify the unique traits it yields and with that knowledge we can then categorize them in groups and specify them by scientific name. These experiments included the Triple-sugar iron agar (TSIA), Sulfur Indole Motility (SIM), Methyl Red (MR), Voges-Proskauer (VP), Citrate, Urease, Gelatin, and Oxidase Test. In order for these tests to produce reliable and credible results, the bacterium organism must be grown using strict and meticulous procedure to produce viable colonies of pure culture. Having pure culture is significant to ensure that a single type of bacteria is used for identification without contamination so tests can be run without complications or confusion. Once all these tests are performed, the unknown bacteria in this lab will be one of the following: Escherichia coli, Enterobacter aerogenes, Proteus mirabilis, Klebsiella pneumoniae, or Salmonella typhimurium. This report included the results and details to these experiments which are discussed further on.


Abstract
Gram negative bacteria Unknown #12 was run through an array of tests which produced positive and negative results. The results obtained from the various tests were used for the process of elimination with the use of our Gram Negative Unknown chart to conclude that unknown #12 was Proteus mirabilis. This report will include information regarding the methods and materials used as well as the discussion about the biochemical tests and the results.

Materials and Methods
The first step in the process of identifying the unknown bacteria...