Test upon test upon test!!!

We did so many more tests in lab!

These experiments included a Catalase test, culturing Anaerobic bacteria, an DNA Hydrolysis test and seeing how our bacteria grew on a blood agar plate, an Eosin Methylene Blue (EMB) Agar, a Mannitol Salt Agar, a MacConkey Agar, a Phenylethyl Alcohol (PEA) Agar.

First our professor had us do a streak plate of our bacteria on a nutrient agar plate. At first we did not know what to do with it but then we found out that we would do a catalase test with that streak of bacteria. With the catalase test, we added a few drops of 3% of hydrogen peroxide to our streak of bacteria. It was really cool to see that our bacteria use the enzyme catalase to quickly break down H2O2 into water and O2 (as shown below)

We then obtained a thioglycollate broth to inoculate with our bacteria.

By inoculating a thioglycollate broth we will be able to cultivate bacteria that cannot survive in the presence of oxygen.

Next we used the aseptic technique to inoculate all of these agar plates with an inoculating loop full of our bacteria. We had a little bit of fun by writing our own initials or the initials of our school on the agar plates.

We first inoculated our blood agar plate.

Now we just have to incubate the plate for two days and see if our bacteria are able to lyse red blood cells.

Now onto the Eosin Methylene Blue (EMB) Agar plate. We again did the aseptic technique with an inoculating loop full of bacteria.

We then put the EMB plate into the incubator for two days and after two day we will see if our bacteria are gram-negative enteric bacilli.

Next is the Mannitol Salt Agar.

For this test we will be able to isolate our bacteria based on their salt tolerance and differentiate among these isolates for mannitol fermentation.

Then we inoculated a MacConkey Agar.

If you can see we had a little by putting the initials of our school on the agar plates. Anyways for this test we are able to detect if our bacteria are gram-negative enteric bacilli, based on their ability to grow on the medium and to ferment lactose.

Our next agar plate that we inoculated was a Phenylethyl Alcohol (PEA) Agar.

For this test we will be able to isolate gram-positive bacteria if our bacteria has a mixture of gram-positive and gram-negative bacteria.

Finally we inoculated a DNA agar plate for a DNA Hydrolysis test.

For this test we will be able to see if our bacteria are able to hydrolyze (digest) DNA.

We incubated all of these plates and broth tube at 37 degrees Celsius and we will see what our bacteria can and cannot do!