Salmonella

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Salmonella enterica (#11)

Gram Negative Organism| CarbohydrateFermentation(PRL)| CarbohydrateFermentation(PRG)| Indole productionTest| MethylRed Test(MR)| VogesProskauer Test| Citrate Utilization Test| Hydrogen sulfide Test| Urease Test| CatalaseTest | Salmonellaenterica| (-)Red color| (+)YellowColor | (-)No red ring| (+)RedRing| (-)No pink| (+)Blue With growth| (+)Black PrecipitateVery motile| (-)No change in color| (+)|

The unknown organism (#11) was Salmonella enterica, which is a rod-shaped, Gram negative organism. They are non-spore forming; very motile .These organisms are chemoorganotrophs (an organism that obtains energy from the oxidation of reduced organic compounds). Salmonella enterica makes ATP by aerobic respiration if oxygen is present but also can switch to fermentation in the absence of oxygen (facultative anaerobes). Salmonella bacteria do not maintain the crystal violet dye used in the gram staining method because of their cell walls that are thin .most of the gram negative bacteria are usually harmful to the host. (Gram negative rod shape salmonella entrica) There are several tests and experiments that classified the genus of the unknown species, which known as gram staining method. Carbohydrate fermentation: 1) Phenol red lactose broth. 2) Phenol Red Glucose broth. 1) Phenol red lactose broth test

This test is used in order to indicate whether the organism can use lactose as the source of energy or not. Phenol red indicator also added in the broth. In this experiment the color remained red and didn’t change which makes the test negative. It means that the organism didn’t ferment with phenol red lactose (PRL). 2) Phenol Red Glucose broth test

In this test if glucose can be used by an organism it will collect acidic byproducts. In this case a positive test was observed, Phenol red is red at the neutral pH,...
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