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Unknown Bacteria By Gram Staining And A Series Of Biochemical Test

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The main purpose of this study is to identify the given unknown bacteria by gram staining and a series of biochemical test. There are many types of bacteria and they produce different enzymes. However, Some bacteria produces same enzymes, so specific tests were done to identify the particular enzymes. There are four main types of Gram-negative bacteria, which are Escherichia coli, Klebsiella pneumonia, Enterobacter aerogenes, and Salmonella typhimurium. Therefore, the unknown could be any of these four bacteria’s, so the main goal of this experiment is to identify the particular unknown bacteria. After doing all the biochemical tests, which includes Triple Sugar Iron Agar test, Sulfur Indole Motility test, Methyl Red test, Voges- Proskauer test, Citrate test, Urease test, and Gelatin test, which took 24 hours incubation time results proved that the given unknown gram negative bacteria was found to be Escherichia coli. II. Introduction In both Gram-negative and Gram-positive bacteria, the cell wall is constructed from the polymer peptidoglycan, a composite of long strands of glycan’s cross-linked by stretchable peptides. (Cited). There are two types of bacteria Gram positive and Gram negative. The peptidoglycan layer distinguishes the bacteria’s. The Gram Positive bacteria have cells with thicker layer of peptidoglycan whereas, …show more content…

It is a semi solid media, which require the specific technique to get an accurate result. Nutrient gelatin is a simple test medium that is composed of gelatin, peptone, and beef extract. Therefore, nutrient gelatin is used to test for the presence of gelatinase. This test require long period of time to give the perfect result. It is inoculated and incubated for up to 8 days. After incubated then chilled for one hour, if the gelatin become solid that means it is negative for gelatinase test however, if the gelatin is liquefied, it is positive for that

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