LAB 3 food microbiology A

Question 1

what is fermentation

Answer 1

a process which releases energy form organic compounds such as sugar which uses an organic molecules as the final electron acceptor

Question 2

what makes sauerkraut fermentation different from other forms of fermentation

Answer 2

it does not require a starter culture rather its the bacteria present on the Cabbage leaves which preform the fermentation

Question 3

what is floral succession

Answer 3

floral succession is a type of fermentation that sees some bacterial species die out as the envoirment changes which is followed by a new species becoming dominant

Question 4

the Floral succession seen in the saurkraut fermentation

Answer 4

1)Salt tolerant gram negative anaerobic bacteria (coliform) ferment sugars in the cabbage juice which produce lactic acid lowering the pH

2) Salt tolerant gram negatives decline in population size and Salt and acid tolerant bacteria (leuconostoc) become dominate

3) lactic acid contiunes to be produced which resluts in a decline in the leuconostoc and a increase in Lactobacillus bacteria

Question 5

why is it important to insure that the sauerkraut is free of oxygen during fermentation

Answer 5

This is because anerobic bacteria may contaminate the process causing spoilage

Question 6

what does PCA isolate for

Answer 6

Aerobic bacteria

Question 7

what does MAC isolate for

Answer 7

gram negative

Question 8

what does HIAS isolate for

Answer 8

for identification of both
leuconostoc and lactic acids bacteria