Lab 22: Fermentation of Carbohydrates

Question 1

fermentation refers to?
-possible end products?

Answer 1

-anaerobic degradation of a substance, in this case carbohydrates
-possible end products include acid, alcohol, and gas (CO2)

Question 2

-fermentation broth is used to determine?
-broth contains?

Answer 2

-the ability of microbes to attack (utilize) various carbohydrates
-contains type of carbohydrate (mannitol, sucrose, glucose or lactose) and phenol red and peptone

Question 3

yellow color change indicates?
-no change?
-deeper red?

Answer 3

-acidic conditions and fermentation has occurred
-no change means carbohydrates were not attacked
-deeper red means production of alkaline

Question 4

results for E. aerogenes?

Answer 4

positive for glucose, mannitol, sucrose, and lactose

Question 5

results for P. vulgaris?

Answer 5

positive for glucose and sucrose
negative for lactose and mannitol

Question 6

results for A. faecalis

Answer 6

negative for glucose, mannitol, sucrose and lactose