Double Unknown Lab Report

1. Title:
Double unknown identification of a mixed culture of Gram-negative and Gram-positive bacteria
2. Author:
Nick Fiore, University of Kansas, Biology 402, Fall 2014 3:00pm room 6040
3. Abstract:
The purpose of this experiment was to isolate two unknown bacteria and perform a series of selective and differential tests to correctly identify each. After the bacteria was isolated a series of differential and selective tests following the dichotomous key attached were used to identify each bacteria. The Gram-positive bacteria were identified as Staphylococcus aureus with a positive confirmatory test, mannitol salt agar, showing consistent results as well for S. aureus. The Gram-negative bacteria were Pseudomonas aeruginosa with a positive confirmatory
Results: The following tables are each corresponding to either the Gram-positive sample or Gram-negative sample and include the tests utilized along with their results all in the order each test was performed. In section 10, Figures, there are some pictures corresponding to the stains performed. In Figure 1, the Gram-positive stain, you can clearly see the purple color and cocci morphology in grapelike clusters. Figure 2 is the Gram-negative stain with the safranin color and shows bacilli cellular morphology. Gram-positive sample
Test Utilized
Result
Controls Gram Stain
Gram-positive cocci
Positive-S. epidermidis
Negative- E. coli
Hemolysis Test
Full clearing of agar, Beta- Hemolysis
Beta- S. pyogenes
Alpha- S. pneumonia
Gamma- E.faecalis
Catalase Test
Bubbles formed, positive
Positive- S. aureus
Negative- E.