Deck 28: Applied and Industrial Microbiology

Question 1

Spoilage of canned foods stored at high temperatures, accompanied by gas production, is

A) Thermophilic anaerobic spoilage.
B) Flat sour spoilage.
C) Spoilage by mesophilic bacteria.
D) Caused by acid- tolerant fungi.
E) Putrefactive anaerobic spoilage.

Answer 1

A

Question 2

Figure 28.1

In Figure 28.1, assume that a secondary metabolite is your desired product. When would you be able to obtain it?

A) a
B) b
C) c
D) d

Answer 2

C

Question 3

All of the following are produced using microbial fermentations except

A) Saccharin.
B) Aspartame.
C) Citric acid.
D) MSG.
E) Riboflavin.

Answer 3

A

Question 4

Canning preserves food by

A) Aseptic packaging.
B) Radiation.
C) Heating.
D) Chemicals.
E) All of the above.

Question 5

Figure 28.1

In Figure 28.1, assume you want an enzyme that is not secreted. You would harvest at the end of what time?

A) a
B) b
C) c
D) d

Question 6

Assume that you bought a semisoft cheese such as blue cheese and put it in your refrigerator. Three weeks later you cut the cheese and notice the center is now liquid because

A) Fungi have accumulated in the center.
B) Fungal enzymes have made more curd.
C) Lactic acid bacteria have grown in the center.
D) Fungal enzymes have digested the curd.
E) None of the above.

Question 7

When compared to a flask culture, a bioreactor offers all of the following advantages except

A) Aseptic sampling.
B) Instrumentation for monitoring environmental conditions.
C) Uniform aeration and mixing.
D) Larger culture volumes can be grown.
E) None of the above.

Question 8

Cellulase attached to a membrane filter will

A) Do nothing; it requires a cell.
B) Degrade the membrane.
C) Degrade lactose.
D) Degrade cellulose.
E) None of the above.

Question 9

Spoilage due to can leakage after processing is

A) Thermophilic anaerobic spoilage.
B) Flat sour spoilage.
C) Spoilage by mesophilic bacteria.
D) Caused by acid- tolerant fungi.
E) Putrefactive anaerobic spoilage.

Question 10

Which of the following is an undesirable contaminant in wine- making?

A) Bacillus
B) Clostridium
C) Acetobacter
D) Lactic acid bacteria
E) Saccharomyces (yeast)

Question 11

If the lac operon is used as a receptor for the lux operon, the presence of lactose would cause the cell to

A) Produce lactose.
B) Grow better.
C) Emit light.
D) Use light energy.
E) Die.

Question 12

Which reaction leads to all the others?

A) Ethanol ?Acetic acid
B) Sucrose ?Ethanol
C) Malic acid ?Lactic acid
D) Carbon dioxide ?Sucrose
E) None of the above

Question 13

Which reaction makes wine less acidic?

A) Sucrose ?Ethanol
B) Malic acid ?Lactic acid
C) Carbon dioxide ?Sucrose
D) Ethanol ?Acetic acid
E) None of the above

Question 14

All of the following are produced using microbial fermentations except

A) Blue cheese.
B) Yogurt.
C) Ice cream.
D) Sour cream.
E) None of the above.

Question 15

Radiation is used for all of the following except

A) Preventing sprouting.
B) Killing Trichinella.
C) Killing insect eggs and larva.
D) Sterilizing food.
E) Foods that cannot be heated.

Question 16

Fermentation works to preserve foods because of this:

A) Anaerobic environment
B) Anaerobic environment and heat
C) Heat
D) Lethal mutations
E) pH

Question 17

What will be produced if wine is aerated?

A) CO₂ + H₂O
B) CH4
C) Ethyl alcohol + CO₂
D) Acetic acid
E) None of the above

Question 18

Radiation and canning are used for all of the following reasons except to

A) Prevent diseases.
B) Prevent spoilage of foods.
C) Sell more food.
D) Prolong the shelf life of foods.
E) All of the above.

Question 19

Radiation works to preserve foods because of this:

A) Anaerobic environment
B) Anaerobic environment and heat
C) Heat
D) Lethal mutations
E) pH

Question 20

Microorganisms themselves are commercial products. Which of the following microbes is available in retail stores?

A) Saccharomyces
B) Lactobacillus
C) Rhizobium
D) Bacillus thuringiensis
E) All of the above

Question 21

You are growing Bacillus subtilis in a bioreactor and notice that the growth rate has slowed and the pH has decreased. What could you do?

A) Add peptides.
B) Add glucose.
C) Add lactose.
D) Add oxygen.
E) None of the above.

Question 22

All of the following are industrial products produced by microbes except

A) Amino acids in food supplements.
B) Uranium.
C) Industrial enzymes.
D) Antibiotics.
E) Vitamin B12 and riboflavin.

Question 23

Which of the following pairs is mismatched?

A) Penicillium - blue cheese
B) Acetobacter - vinegar
C) Propionibacterium - Swiss cheese
D) Bacillus - hard cheese
E) Streptococcus - yogurt

Question 24

Canning works to preserve foods because of this:

A) Anaerobic environment
B) Anaerobic environment and heat
C) Heat
D) Lethal mutations
E) pH

Question 25

You are growing Bacillus subtilis in a bioreactor and notice that the growth rate has slowed and the pH has decreased. You suspect the bacteria are

A) Using the Krebs cycle.
B) Using proteins.
C) Fermenting.
D) Photosynthesizing.
E) None of the above.

Question 26

All of the following are industrial enzymes made by microbial fermentations except

A) Cellulases.
B) Glucose isomerase.
C) Proteases.
D) Rennin.
E) None of the above.

Question 27

Which of the following food additives is not produced by microorganisms?

A) Citric acid
B) Glutamic acid
C) Protease
D) Amylase
E) Sodium nitrate

Question 28

Figure 28.3

Which of the growth curves in Figure 28.3 will give the highest yield of a secondary metabolite?

A) a
B) b
C) c
D) d
E) e

Question 29

Aseptic packaging works to preserve foods because of this:

A) Anaerobic environment
B) Anaerobic environment and heat
C) Heat
D) Lethal mutations
E) pH

Question 30

Spoilage of canned foods due to inadequate processing, not accompanied by gas production, is

A) Thermophilic anaerobic spoilage.
B) Flat sour spoilage.
C) Spoilage by mesophilic bacteria.
D) Caused by acid- tolerant fungi.
E) Putrefactive anaerobic spoilage.

Question 31

Your friend says he had stored a semisoft cheese (blue cheese) in his refrigerator for three weeks. He asks you why the outer "skin" of the cheese is so much thicker than it was when he originally purchased the cheese. You tell him that

A) Fungal enzymes have made more curd.
B) Fungal enzymes have digested the curd.
C) Fungi have been growing.
D) Lactic acid bacteria have grown on the outside.
E) None of the above.

Question 32

Ethanol for automobile fuel is produced from corn by

A) The Krebs cycle.
B) Fermentation.
C) Anaerobic respiration.
D) Oxidation.
E) None of the above.

Question 33

Microbial products can be improved by

A) Mutating existing strains.
B) Isolating new strains.
C) Genetically engineering strains.
D) Modifying culture conditions.
E) All of the above.

Question 34

Figure 28.2

Which of the graphs in Figure 28.2 shows the pH in a culture flask as cells metabolize glucose and then protein?

A) a
B) b
C) c
D) d
E) e

Question 35

Wine is made from fruit juices by

A) Anaerobic fungal growth.
B) Bacterial production of CO₂.
C) The addition of sugar.
D) The addition of alcohol.
E) Malting.

Question 36

Commercial sterilization differs from true sterilization in that commercial sterilization

A) May result in the survival of fungal spores.
B) May result in the survival of thermophiles.
C) Kills only bacteria.
D) Employs a higher temperature.
E) Kills all microorganisms.

Question 37

The following steps are required for making cheese. What is the second step?

A) Inoculate with lactic acid bacteria
B) Enzymatic coagulation of milk
C) Separate curds and whey
D) Fermentation of curd
E) Press curd

Question 38

Figure 28.1

In Figure 28.1, assume that cells are your desired product. When would you harvest cells to maximize your yield?

A) a
B) b
C) c
D) d

Question 39

Methane made from biomass is produced by

A) Oxidation.
B) Anaerobic respiration.
C) The Krebs cycle.
D) Fermentation.
E) None of the above.

Question 40

Figure 28.3

Figure 28.3 shows the growth curves of Acetobacter under different conditions. Which culture would have the highest amount of acetic acid?

A) a
B) b
C) c
D) d
E) e

Question 41

Which of the following is not an alternative fuel (energy source) produced by bacteria?

A) Methane
B) Ethyl alcohol
C) Hydrogen
D) Methyl alcohol
E) Lactic acid

Question 42

As cheese ages it gets

A) Saltier.
B) More whey.
C) More protein.
D) More acidic.
E) None of the above.

Question 43

A product made late in log phase and in stationary phase is called

A) A secondary metabolite.
B) An idiotypic metabolite.
C) Undesirable.
D) Fermentation.
E) None of the above