The goal of this enrichment culture was to isolate the organism Streptococcus thermophilus.  First we chose the environment from which we would like to isolate the bacteria from: yogurt.  We then researched which organisms are used in the production of yogurt and chose one to isolate.  Next, we investigated the type of media and environmental conditions that would best support this organism.

    Our hypothesis was that we would be able to successfully isolate S. thermophilus if certain conditions we had researched were provided during growth.  One condition is the use of HYA agar, which provides digested enzymes (proteose peptone #3) and three sugars (glucose, lactose, and galactose) that the organism is able to metabolize.  These plates were incubated at 37 degrees Celcius, which allows for maximum growth.  We found the recipe for the HYA agar in Atlas' Handbook of Microbiological Bacteria. The book stated that this  media would allow for the growth of S. thermophilus or Lactobacillus bulgaris.