The Catalase Test Of The Gram Staining And Observing Which Unknown Culture Is Gram Positive

1742 Words Dec 1st, 2015 null Page
Discussion: Each test is a pertinent contribution to drawing an educated conclusion. After performing the gram staining and observing which unknown culture was gram positive, a catalase test was performed. The catalase test allows lab workers to differentiate Staphylococci and Streptococci genus. The test was performed only on the gram-positive culture. Bacteria that respire by the use of oxygen, otherwise known as aerobic respiration, produce enzyme or “catalase”. This protects the bacteria from the harmful by-product produced from oxygen metabolism that would normally be bactericidal. A positive reaction here would present visible bubbling. A negative reaction would be no reaction or no bubbles produced. Due to no bubbles being produced this leads us to our next set of tests to perform on the unknown. With this knowledge of a negative catalase test we proceed to perform a verity of other environmental requirement/reaction tests. This Includes incubation of the gram positive bacteria on a 6.5% NaCl medium, BHIA (Brain Heart Infusion Agar) medium and a Blood agar medium. Interpretations of these results are as follows.
The NaCl 6.5% medium was used to test the bacteria’s ability to survive in a salt rich environment. Most organisms are unable to survive in this type of environment because it is hostile. This test allows us to confirm and narrow down our results even further. After incubation at 37o Celsius there was no growth on this selective medium, therefore we can…

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