Motility Testing

In lab we did a motility test to find out whether our sample S bacteria have one or more flagella that are propelling the bacteria.

First we have to obtain a sample of bacteria from our sample. We do this by touching the bacteria with a sterile inoculating needle. Then we stab the bacteria into the center of the test medium to about halfway to three-quarters depth.

We also did the same technique with a broth culture.

RESULTS:

After incubating our bacteria at 37 degrees centigrade, we were able to observe that our bacteria is motile!

The bacteria that was in the semisolid agar medium, not only grew along the stab of the innoculating needle, but also swam outward creating a small cloud of bacteria in the test tube. 

We can conclude from this test that our bacteria possesses some sort of flagella, that spins in a corkscrew motion and propels the bacteria making it motile.

We further tested our bacteria's motility by observing the broth we incubated on a microscope slide. 

To do this we had to make a hanging drop slide. 

We first got a clean depression slide a coverslip and some petroleum jelly. 

On the corners of the coverslip we put four small dots of petroleum jelly.

 Then using a sterile innoculating loop we obtained a bead of our bacteria from the broth culture, and put that bead in the center of our coverslip. 

Next we gently put the cover slip on the depression slide. This resulting in the drop hanging over the depression in the slide so that bacteria could be viewed swimming within the drop.

This procedure proved to be very difficult for us, and it took us multiple tries to to be able to actually see the bacteria. When we finally did, we confirmed (with alot of help from Dr. P) that our bacteria was motile!

 We were able to see our rod shaped bacteria actually swimming around!!