Microbiology Lab ReportPractica #1BTC307LAmber AmelingmeierThursday, September 18, 2008OBJECTIVESIn this lab experiment two different types of bacteria, Escherichia coli and Staphylococcus aureus, were grown singly and mixed on four different types of agar in order to observe the varying morphologies within the colonies. Resulting data was analyzed to provide understanding of the use of differing culture media and conditions for bacterial growth.
RESULTSFour different agar types were used in this experiment. The first (Nutrient) allowed for growth of both E. coli and S. aureus. The second agar used (MKL) inhibited the growth of S. aureus but allowed the growth of E. coli. The third (ASH) yielded growth of both bacterial species. The
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These color change occurrences are indicative of pH changes within the agar dishes. The MKL agar is both selective and differential, and is thus is able to identify lactose degradation due to the presence of a pH indicator. When a lactose-positive colony such as E. coli is inoculated on the agar, the decrease in pH yields a change in color on the agar and the