October 11, 2011
On this day I did multiple procedures. First I froze some bacteria by adding 850 microliters of broth culture to a microcentrifuge tube using a micropipettor and then using the micropipettor again I added 150 microliters of glycerol. I then sealed and stored it in a -70 degrees Celsius drawer of a freezer. Next I prepared a tube of thioglycollate broth to have my unknown inoculated and tested to see if it is an aerobe or anaerobe and what kind it is. After inoculating I sealed the tube but left it loose so oxygen could get in. Another test the whole lab did for their unknowns was to prepare streak plates to place in a GasPak Anaerobic System which would keep out oxygen. The oxygen indicator strip was blue when it was out of the container but when it was sealed it slowly lost color. The container was put in an incubator and the last group experiment started. We learned another way to test if bacteria was anaerobic or not was to put it in an air-tight jar and light a candle to use up the oxygen and see if any bacteria grew or not.
October 13th, 2011
On this day my goal was to prepare tests to see if my unknown bacteria reacted to starch, casein, or triglyceride. I made a line on each plate carrying the medium and put them in the incubator. I checked my thioglycollate tube and found that it did not inoculate properly so I had to make a new one. I also checked my plate in the GasPak Anaerobic System and found that my plate barely grew any bacteria at all, which points to the possibility of being an aerobe.
Anaerobic Test
October 14th, 2011
I checked my thioglycollerate tube to see if bacteria grew this time and I found it growing everywhere in the tube, suggesting it is a facultative aerobe. There was not any growth on the casein plate which indicates a negative reaction. Even though there was growth on the starch and triglyceride plates there was no blue precipitate anywhere on the triglyceride plate which means that it is negative. When Gram’s Iodine was applied to the starch plate, a black-blue precipitate formed which meant that it was also negative for starch but positive for amylase.
Starch
Casein
Triglyceride Thioglycollerate
