24 Tube Inoculating

We inoculated tubes containing sucrose, glucose, lactose or nutrient gelatin. The liquid tubes are to test carbohydrate utilization. These tubes also conatined a durham tube which is used to indicate gas production. The tubes all had Phenol-red as the ph indicator. This procedure is done to determine if a microbe is facultative, deriving it's energy from fermentation. The fermentation will result in acid production which will lower the pH of the broth and the broth will turn yellow. If not full yellow, the result is negative. Some organisms will also produce amonia and CO2. The durham tube will capture this any gas produced.
The gelatin tubes are to show gelatin hydolysis from the enzyme gelatinase. The protein gelatin is digested by some organisms. This test determines if the microbe does or does not produce gelatinase. If the organism does, the gelatin will change from solid to liquid.
We also made a Qudrant streak plate on Starch Agar and Tributyrin Agar streaked with E. coli, Bacillus subtilis and our unknown. Starch agar selects organisms that produce the enzyme amylase to break down starch. Starch hydrolysis is indicated by a clear zone due to the action of amylase.
Tributyrin Agar is used to show fat hydrolysis by the enzyme lipase. Organisms that can hydrolysize fat will have a clear zone around their colony.

24 Test Tubes Inoculating.....

Today we inoculated tubes of sucrose, lactose, glucose and nutrient agar with E. coli, Bacillus subtilis, Staph. aureus and our unknown. We also did a quadrant streak on Tributyrin Agar and Starch Agar with E. coli, Bacillus subtilis and our unknown. I still think my known is Staph aureus, but have done little in the last month or so to progress beyond my intial guess.

Mucho Media!

This test indicates that I test negative for dental caries at both 24 and 48 hours. This explains why I never have cavaties. Lucky me, I've inheritted my father's good teeth. My brother on the other hand would probably have a yellow tube at 24 & 48 hours. This means he has marked risk for dental caries. He has my mother's bad teeth or should I saw destructive mouth flora? He has frequent cavaties and problems with his teeth. Count you blessings if you have a green tube!
Here is a face skin culture on a Blood Agar plate. Microbe shows Gamma-Hemolysis (none) created small white circular colonies. Organism is most likely non-aureus Staph, which is considered normal skin flora. Skin from my arm on blood agar. 2 microbes arose. 1 was Beta-hemolytic (complete lysis) and is the large yellow growth. The other was Gamma-hemolytic (no lysis) and is the small round white colonies. The first microbe is most like bacillis normally found in the soil but can sometimes be found as skin flora. The second is most likely non-aureus Staph. Both are considered to be normal skin flora.