Bio 2010 - Microbiology » Summer 2021 » Lab Quiz 4

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Question #1
After incubating your bacterium in potassium nitrate (KNO3) broth, you add alpha naphthylamine and sulfanilic acid. The broth immediately turns red. This result indicates the presence of which enzyme(s)?
A.   super peroxidase
B.   catalase
C.   nitrate reductase
D.   more than one of the above is correct
E.   nitrite reductase
Question #2
Among the Gram-positive organisms, Enterococcus durans is one of the few organisms that is not inhibited by the presence of bile salts. Which of the following is the most likely explanation?
A.   it grows well on skin or the integument system tissues, which have high bile salt concentrations
B.   it grows well in nervous system tissues, which have high bile salt concentrations
C.   it grows well in digestive system tissues, which have high bile salt concentrations
D.   it grows well in the pulmonary system tissues, which have high bile salt concentrations
Question #3
From the IMVIC test series, which of the following enzymes is needed to convert tryptophan into indole?
A.   tryptophanase
B.   mannitol deyhydrogenase
C.   tryptase
D.   catalase
E.   indolase
Question #4
Suppose you are a microbiology laboratory technician. You have a culture with mixed bacteria. Your boss asks you to isolate the Gram-positive organisms ONLY. Which of the following media would the MOST appropriate media to begin isolating Gram-positive organisms?
A.   Columbia CNA agar
B.   DNAse agar
C.   Starch Agar
D.   MacConkeyâ s agar
E.   Skim Milk Agar

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