24 SIM Medium Assignment
Emilie Miller, Ph.D
Data and Observations
Sulfur Reduction
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Motility
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Indole Production
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Post Lab Questions
- Would this medium be considered selective, differential or both?
2. What is the purpose of comparing your results to an uninoculated inoculated tube?
3. The inability of this test to distinguish between H2S produced by putrefaction and H2S produced by reduction in the final step of an anaerobic ETS, can be described as poor in this test system. The indole test determines if the organism has the enzyme tryptophanase. The substrate for this enzyme is:
4. What component of the medium supplies this substrate?
Predict what your observations would look like for Citrobacter freundii if you made each of these mistakes in preparing the medium. Explain in one sentence.
5. Used 15 g/L agar
6. Left out the ferrous ammonium sulfate Fe(NH4)2(SO4)
7. Left out sodium thiosulfate Na2S2O3
8. If you left out the sodium thiosulfate would that increase the specificity or sensitivity of the test?