The Taste of Biotech, Kochs Postulate Related to Yogurt

Before germs were discovered, bad bacteria was taking millions of lives. It was a mystery as to why these lives were being taken. By the 1800s physicians started finding reasoning as to why people were getting sick and dying. The first major stride towards understanding bacteria was Koch postulate. This system helped isolate the ideas and study it's effects. Bacterial ideas has played a major role in human history because humans have faced dieases like cholera, typus, the bubonic plague, tubculouis and others. As humanity progressed we have discovered the use of antibiotics to destroy these harmful bacteria. While we have found ways to destroy bacteria we have also found ways to use bacteria to our benefits. Bacteria is in food, and it is nessary in the manufacturing of products such as cheese, kimchi, sir cream, pikels and most importantly yogurt.
The purpose of this experimentation is to test kochs postulate while observing the effects of the bacteria or yogurt on milk. We will be using different test tubes one with a negative contrlol(just milk),a positive control with yogurt, a tube with ampicillin, and lasty a tube with e.Coli. We will the observe the tubes and run tests. My hypotheses is that the positive control will turn into yogurt while the negative control will just spoil.

We observed little change in any of the tubes. The positive Control of the tube with just milk appeared to have spoiled a little but the three others were just about the exact same as they were the day before. http://www.youtube.com/watch?v=rIwI2CQUZdw

The reasoning behind the little to no activity in the yogurt milk samples might be attributed to lack of time. WE could have not let the yogurt complete its cycle and fully turn into yogurt. Although in the negative control with the trace amounts of yogurt sample we found it did smell sweeter than the others so maybe it was on the right track and turning into yogurt. The sample with E. Coli was the only sample with a higher pH, which was 7. The other three were still 6. Some possible sources of error might include not putting in a sufficient amount of yogurt bacteria, or maybe not vortex and mix around the sample for long enough, or not letting the yogurt have enough time to fully develop.