Microbiology, 9e (Tortora) Chapter 28 Objective Questions 1) 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. 2) 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)
Transcript
Microbiology, 9e (Tortora)Chapter 28
Objective Questions
1)
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.
2)
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.
3)
Spoilage of canned foods due to inadequate processing, not accompanied by gas production, is A)
Microbiology, 9e (Tortora)Chapter 28
Thermophilic anaerobic spoilage. B)
Flat sour spoilage. C)
Spoilage by mesophilic bacteria. D)
Caused by acid-tolerant fungi. E)
Putrefactive anaerobic spoilage.
4)
Which of the following pairs is mismatched? A)
Propionibacterium Swiss cheese B)
Penicillium blue cheese C)
Streptococcus yogurt D)
Acetobacter vinegar E)
Bacillus hard cheese
5)
Which of the following is not an alternative fuel (energy source) produced by bacteria? A)
Lactic acid B)
Methyl alcohol C)
Ethyl alcohol
Microbiology, 9e (Tortora)Chapter 28
D)
Hydrogen E)
Methane
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6)
Which of the following food additives is not produced by microorganisms? A)
Amylase B)
Citric acid C)
Sodium nitrate D)
Glutamic acid E)
Protease
7)
Wine is made from fruit juices by A)
The addition of alcohol. B)
Bacterial production of CO2. C)
The addition of sugar. D)
Anaerobic fungal growth. E)
Malting.
8)
Which of the following is an undesirable contaminant in wine-making? A)
Acetobacter B)
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Lactic acid bacteria C)
Clostridium D)
Bacillus E)
Saccharomyces (yeast)
9)
Commercial sterilization differs from true sterilization in that commercial sterilization A)
Kills all microorganisms. B)
Kills only bacteria. C)
May result in the survival of thermophiles. D)
Employs a higher temperature. E)
May result in the survival of fungal spores.
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Figure 28.1
10)
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
11)
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
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12)
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
13)
Which reaction leads to all the others? A)
Sucrose → Ethanol B)
Ethanol → Acetic acid C)
Malic acid → Lactic acid D)
Carbon dioxide → Sucrose E)
None of the above
Microbiology, 9e (Tortora)Chapter 28
14)
Which reaction makes wine less acidic? A)
Sucrose → Ethanol B)
Ethanol → Acetic acid C)
Malic acid → Lactic acid D)
Carbon dioxide → Sucrose E)
None of the above
15)
If the lac operon is used as a receptor for the lux operon, the presence of lactose would cause the cell to A)
Die. B)
Emit light. C)
Produce lactose. D)
Grow better. E)
Use light energy.
16)
When compared to a flask culture, a bioreactor offers all of the following advantages except A)
Larger culture volumes can be grown. B)
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Instrumentation for monitoring environmental conditions. C)
Uniform aeration and mixing. D)
Aseptic sampling. E)
None of the above.
17)
Microbial products can be improved by A)
Isolating new strains. B)
Mutating existing strains. C)
Genetically engineering strains. D)
Modifying culture conditions. E)
All of the above.
18)
Cellulase attached to a membrane filter will A)
Degrade cellulose. B)
Degrade the membrane. C)
Do nothing; it requires a cell. D)
Degrade lactose.
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E)
None of the above.
Microbiology, 9e (Tortora)Chapter 28
Figure 28.2
19)
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
20)
All of the following are industrial products produced by microbes except A)
Amino acids in food supplements. B)
Antibiotics. C)
Industrial enzymes. D)
Uranium. E)
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Vitamin B12 and riboflavin.
21)
All of the following are produced using microbial fermentations except A)
Aspartame. B)
Citric acid. C)
MSG. D)
Riboflavin. E)
Saccharin.
22)
All of the following are produced using microbial fermentations except A)
Blue cheese. B)
Ice cream. C)
Sour cream. D)
Yogurt. E)
None of the above.
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23)
Which of the following is an oxidation reaction that Thiobacillus ferooxidans might do? A)
Fe3+ → Fe2+ B)
U4+ → U6+ C)
Cu2+ → Cu+ D)
Cu+ → Cu0
E)
Al3+ → Al2+
24)
Methane made from biomass is produced by A)
Anaerobic respiration. B)
Fermentation. C)
The Krebs cycle. D)
Oxidation. E)
None of the above.
25)
All of the following are industrial enzymes made by microbial fermentations except A)
Glucose isomerase. B)
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Rennin. C)
Proteases. D)
Cellulases. E)
None of the above.
26)
Ethanol for automobile fuel is produced from corn by A)
Anaerobic respiration. B)
Fermentation. C)
The Krebs cycle. D)
Oxidation. E)
None of the above.
27)
The following steps are required for making cheese. What is the second step? A)
Enzymatic coagulation of milk B)
Fermentation of curd C)
Inoculate with lactic acid bacteria D)
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Press curd E)
Separate curds and whey
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28)
As cheese ages it gets A)
More acidic. B)
More whey. C)
More protein. D)
Saltier. E)
None of the above.
29)
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)
Lactic acid bacteria have grown in the center. B)
Fungal enzymes have digested the curd. C)
Fungal enzymes have made more curd. D)
Fungi have accumulated in the center. E)
None of the above.
30)
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)
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Lactic acid bacteria have grown on the outside. B)
Fungal enzymes have digested the curd. C)
Fungal enzymes have made more curd. D)
Fungi have been growing. E)
None of the above.
31)
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)
Fermenting. C)
Photosynthesizing. D)
Using proteins. E)
None of the above.
32)
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 glucose. B)
Add lactose. C)
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Add peptides. D)
Add oxygen. E)
None of the above.
33)
Radiation and canning are used for all of the following reasons except to A)
Prevent diseases. B)
Prolong the shelf life of foods. C)
Prevent spoilage of foods. D)
Sell more food. E)
All of the above.
34)
Radiation is used for all of the following except A)
Foods that cannot be heated. B)
Sterilizing food. C)
Killing Trichinella. D)
Killing insect eggs and larva. E)
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Preventing sprouting.
35)
Canning preserves food by A)
Aseptic packaging. B)
Chemicals. C)
Heating. D)
Radiation. E)
All of the above.
36)
Microorganisms themselves are commercial products. Which of the following microbes is available in retail stores?
A)
Bacillus thuringiensis B)
Lactobacillus C)
Rhizobium D)
Saccharomyces E)
All of the above
Microbiology, 9e (Tortora)Chapter 28
Figure 28.3
37)
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
38)
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
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E)
e
39)
Canning works to preserve foods because of this: A)
Anaerobic environment B)
Anaerobic environment and heat C)
Heat D)
Lethal mutations E)
pH
40)
Aseptic packaging works to preserve foods because of this: A)
Anaerobic environment B)
Anaerobic environment and heat C)
Heat D)
Lethal mutations E)
pH
Microbiology, 9e (Tortora)Chapter 28
41)
Radiation works to preserve foods because of this: A)
Anaerobic environment B)
Anaerobic environment and heat C)
Heat D)
Lethal mutations E)
pH
42)
Fermentation works to preserve foods because of this: A)
Anaerobic environment B)
Anaerobic environment and heat C)
Heat D)
Lethal mutations E)
pH
43)
What will be produced if wine is aerated? A)
Ethyl alcohol + CO2 B)
Microbiology, 9e (Tortora)Chapter 28
CO2 + H2O C)
CH4 D)
Acetic acid E)
None of the above
44)
Grape juice before fermentation is called must. What will be produced if must is aerated? A)
Ethyl alcohol + CO2 B)
CO2 + H2O C)
CH4 D)
Acetic acid E)
None of the above
45)
A product made late in log phase and in stationary phase is called A)
