Blog Post week 3

1. Oxidase Test[no color change(-)]

4. Found Unknown (E-Coli!)

Hey everyone! Good news! As you know I had made a mistake last week and had to regrow my cultures. Well they grew! This time I was able to determine under the microscope that my bacteria was a gram negative-bacilli. Using a flow chart, it guided me to the different tests I were to perform to find my unknown. The following three pictures show the results of my tests and the last one is my own flow chart that I made as I performed each test. The first test after identifying it was a gram-negative bacilli, was called the oxidase test. By doing this we determined that it was negative because by placing a drop on a colony, it would either have changed color if it was positive. Next were the glucose fermentation test and the SIM test that I had to leave incubated over a 24hr period. These are the results I found today. For the GFT, I found that it was acid because of the yellow color, and it was a gas by the bubble in the Durham tube. Since we had a positive acid, I was then directed to look at the SIM testing results which was a stab of my bacteria into the tube and found that there was a negative in the reduction of sulfide which if it was positive it would have turned a dark color. I also found that the motility was positive because as you can see, it looks as if it came away from the straight stab that I had made, therefore there was movement, in which it made the motility positive. By performing these tests I have found my unknown!Which is circled on the 4th picture.

2. GFT Yellow color and bubble(+ Acid)

3. SIM (-)Reduction of Sulfur and (+) Motility