Lab 11/8: Nitrate, Citrate, Urea, Indole

Tests for today's lab: Nitrate, Citrate, Urea, Indole:

Nitrate Test determines whether or not our bacteria reduces Nitrate to Nitrite

Citrate Test is to see if our bacteria utilizes citrate as it's Carbon Source.

Urea Test is to determine if our bacteria produces the "urease enzyme"

Indole Test is to see if our bacteria can resist the nucleic acid called tryphotan and make what is known as Indole.

We inoculated 4 test tubes for the following tests: Nitrate, Citrate, Urea, and    Indole. In order to find the results of urea, we will check it in 24 hours. For Nitrate and Indole, a reagent is added in the next lab on Thursday. We also made a streak plate to test 7 different antibiotics on our bacteria. (Say what happens in each of the tests).

Lab 10/27: Mannitol, MacKonkey, EMB tests

Today we inoculated 3 agar plates, Mannitol, Mackonkey, and EMB. We'll look at the results on Tuesday, and figure out whether our bacteria grows in these conditions or not. All three plates are differential mediums to determine the metabolizing capabilities of our bacteria.

The Mackonkey test is a test to differentiate enteric bacteria.
Mannitol Salt is a test to see if our bacteria can grown in especially salty conditions.
EMB: Eosin Methylene Blue test is to differentiate fecal coliforms.

Lab 10/25: Water Filtration Plant and tests

We went to the water filtration plant today to observe the process of treating the water of Steubenville. We also started three tests,

Lab 10/20: Glucose, Lactose, Sucrose, TSIA, Gelatin Results!

Results of these tests from 10/18:

Glucoseà Yellow, meaning it used the sugar, but there was no gas in it (if there was, bubbles would have appeared)

Lactoseà Red

SucroseàYellow, meaning it used the sugar, there was no gas present            here either.

TSIAà Red Slant with a Yellow Butt. The yellow butt indicates that the bacteria maintained growth in acidic conditions, but only the bacteria used the glucose.

Gelatinà We noticed that the bacteria grew in this slant after observing it in room temperature, and then we put this slant in the refrigerator for 15 minute. After taking it out, we noticed that it turned to liquid and therefore, the Gelatin test was positive (a negative test would have been solid). 

Lab 10/18: Sugars, Litmus and TSIA tests

Today, we inoculated 6 different tubes including: Glucose, Litmus Milk, Lactose, TSIA (Triple Sugar Ion Agar), Sucrose, Gelatin. These tests will show whether or not our bacteria will or will not grow in these conditions. 

Lab 10/13: Starch and Caesin Hydrolysis

(Preserving our environmental bacteria)

We found that our bacteria grew in anaerobic conditions, as well as aerobic conditions; therefore, it’s a facultative aerobic bacteria. There was more growth on the top of the Thioglycolate broth, but it still grew throughout the tube. Our next tests are the Starch Hydrolysis Test and the Caesin Hydrolysis Test. We inoculated a Starch Agar plate and another plate for Casein. We also took our environmental bacteria (collected from the bathroom door handle) and put it in a container, where it will be preserved. 

Lab 10/11: Environmental Conditions

Thioglycollate Broth (Above)

Today, we tested our bacteria to figure out whether it uses oxygen, the amount it uses, and if it is tolerant of oxygen. We did this in 2 ways: 1) by inoculating a thioglycollate broth tube, which shows the amount of Oxygen bacteria uses.  2) by putting a sample of our bacteria in the GasPak which makes the environment completely free of O2. In the GasPak, there's an envelope with a paper that indicates whether oxygen is present in the container, or if the container is free of oxygen. You use catalyst called Palladium, which takes out CO2 and replaces it with O2. If there’s O2, the paper turns blue, if there’s no O2, the paper is white. This is how you can tell whether the GasPak is free of O2 or not. We also did the candle in the jar experiment. The burning candle is fueled by the O2 in the environment, but once the cap is put on the jar, all of the oxygen in the jar is used up by the flame and the environment in the jar is free of O2, and CO2 is abundant. Therefore, the flame’s fuel runs out and it dies down.

Lab 10/6: Look Up

(Still have to find in notes)

Lab 10/4: Look up

(Still have to find in notes)