Deck 28: Applied and Industrial Microbiology

Question 1

Figure 28.1

In Figure 28.1, assume the cells are producing penicillin which is collected during the idiophase. When would you be able to collect the penicillin?

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

Answer 1

C

Question 2

Biomass is a renewable energy source derived from the organic matter produced by living organisms. All of the following are sources of biomass EXCEPT

A) crops.
B) landfill sites.
C) algae.
D) oxidation of metals.
E) bacteria.

Answer 2

D

Question 3

What process does yeast use to produce ethanol for automobile fuel from corn?

A) oxidation
B) fermentation
C) photosynthesis
D) anaerobic respiration
E) the Krebs cycle

Answer 3

B

Question 4

Figure 28.3

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

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

Question 5

All of the following are advantages of a bioreactor instead of a flask culture EXCEPT

A) aseptic sampling.
B) uniform aeration and mixing.
C) instrumentation for monitoring environmental conditions.
D) larger culture volumes can be grown.
E) None of the answers is correct; all of these are advantages of using a bioreactor instead of a flask culture.

Question 6

Thiobacillus ferrooxidans is used for the recovery of from ore.

A) sulfuric acid
B) sulfur
C) gold
D) copper
E) iron

Question 7

All of the following are reasons for utilizing algae for biofuel production EXCEPT

A) they can utilize agriculturally poor land.
B) they do not take up land needed for food production.
C) they produce a nondegradable waste product.
D) they produce more energy per acre than corn.
E) their main requirement is abundant light.

Question 8

Figure 28.1

In Figure 28.1, assume the cells are your desired product and you want to maintain a continuous culture. When would you harvest cells to maximize your yield?

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

Question 9

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

A) inoculation with lactic acid bacteria
B) inoculation with Penicillium
C) enzymatic coagulation of milk
D) fermentation of curd
E) separation of curds and whey

Question 10

Commercial sterilization differs from complete sterilization in that commercial sterilization

A) employs a higher temperature.
B) kills only bacteria.
C) may result in the survival of thermophiles.
D) may result in the survival of fungal spores.
E) kills all microorganisms.

Question 11

Canning preserves food

A) by exposure to high heat.
B) through use of aseptic packaging.
C) by exposure to high pH.
D) by exposure to radiation.
E) by exposure to chemicals.

Question 12

Which of the following microorganisms is usually used in the fermentation of alcoholic beverages?

A) Rhizopus
B) Penicillium
C) Propionobacterium
D) Lactobacillus
E) Saccharomyces

Question 13

What will be produced if wine is aerated?

A) CH₄
B) acetic acid
C) ethanol + CO₂
D) CO₂ + H₂O
E) None of the answers is correct.

Question 14

Bioreactors are widely used for industrial fermentation. Which of the following conditions must be closely monitored for optimal fermentation?

A) temperature
B) pH
C) oxygen levels
D) both temperature and pH
E) temperature, pH, and oxygen levels

Question 15

A baker forgets to put yeast in his bread dough. Which of the following do you expect to happen to the bread as a result?

A) The bread will not rise.
B) The bread will look normal but will be tough.
C) It will take longer to bake.
D) Bacterial contaminants will now be able to grow.
E) The bread will have a sour taste.

Question 16

Commercial sterilization of processed canned foods uses a 12D treatment which is based upon a theoretical population of 10¹² C. botulinum endospores in a can of food. After treatment, there would theoretically be how many endospores left?

A) 10 endospores
B) 100 endospores
C) 1 endospore
D) 12 endospores
E) 0 endospores

Question 17

Aseptic packaging works to preserve foods through

A) creation of an anaerobic environment.
B) mutation of bacterial DNA.
C) creation of an anaerobic environment and high heat.
D) exposure to high heat.
E) increasing pH.

Question 18

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

A) proteases.
B) glucose isomerase.
C) rennin.
D) vitamin C.
E) amylases.

Question 19

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

A) Lactobacillus
B) Rhizobium
C) Bacillus thuringiensis
D) Saccharomyces
E) All of these organisms can be found in various commercial products.

Question 20

All of the following foods are produced using microbial fermentations EXCEPT

A) yogurt.
B) ketchup.
C) coffee.
D) sauerkraut.
E) sour cream.

Question 21

Xanthan used in household products is produced by bacteria

A) selected for their ability to utilize lactose.
B) that are plant pathogens.
C) that were genetically modified.
D) that were irradiated to mutate them.
E) selected for their ability to utilize lactose and that are plant pathogens.

Question 22

Microbial products can be improved by all of the following EXCEPT

A) modifying culture conditions.
B) genetically modifying strains.
C) sterilization.
D) isolating new strains.
E) mutating existing strains.

Question 23

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) photosynthesizing.
B) using proteins.
C) fermenting.
D) using the Krebs cycle.
E) dead.

Question 24

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

A) peptides
B) lactose
C) oxygen
D) glucose
E) lactic acid

Question 25

What role do lactic acid bacteria play in cheese production?

A) providing characteristic flavor and smell
B) production of holes in Swiss cheese
C) curd formation
D) ripening the cheese
E) Lactic acid bacteria carry out each of these roles in cheese production.

Question 26

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

A) putrefactive anaerobic spoilage.
B) caused by acid- tolerant fungi.
C) spoilage by mesophilic bacteria.
D) flat sour spoilage.
E) thermophilic anaerobic spoilage.

Question 27

Which of the following reactions makes wine less acidic?

A) ethanol -acetic acid
B) sugar -CO₂ + H₂O
C) carbon dioxide -sucrose
D) sugar -ethanol
E) malic acid -lactic acid

Question 28

All of the following are uses for radiation EXCEPT

A) sterilizing spices.
B) inactivation of Trichinella larvae.
C) heating cold food.
D) prevention of sprouting.
E) killing of insect eggs and larva.

Question 29

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

A) Bacillus
B) Acetobacter
C) Clostridium
D) Saccharomyces
E) lactic acid bacteria

Question 30

Which of the following pairs is mismatched?

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

Question 31

All of the following are industrial products produced using microbial fermentations EXCEPT

A) aspartame.
B) saccharin.
C) citric acid.
D) monosodium glutamate.
E) riboflavin.

Question 32

All of the following are fuels produced by microorganisms EXCEPT

A) methane.
B) hydrogen.
C) ethanol.
D) cellulose.
E) oil from algae.

Question 33

As cheese ages, it gets

A) saltier.
B) more protein.
C) more acidic.
D) more alcoholic.
E) more whey.

Question 34

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

Question 35

Microorganisms play an active role in the formation of industrial products. Which of the following is mismatched?

A) Bacillus thuringiensis - insecticide
B) algae - citric acid
C) Saccharomyces cerevisiae - for fermentation
D) Rhizobium - increases nitrogen in the soil
E) Penicillium - treatment of disease

Question 36

Aseptic packaging utilizes which of the following to sterilize laminated paper or plastic prior to filling with food?

A) X rays
B) hot hydrogen peroxide solution
C) autoclave
D) gamma radiation
E) hot HCl solution

Question 37

Which of the following pertains to an improperly canned food product on a store shelf that bulges from microbial activity?

A) mesophilic spoilage
B) flat sour spoilage
C) thermophilic anaerobic spoilage
D) hydrogen sulfide spoilage
E) bacterial soft rot

Question 38

Canning works to preserve foods through

A) exposure to high heat.
B) increasing pH.
C) mutation of bacterial DNA.
D) creation of an anaerobic environment.
E) creation of an anaerobic environment and high heat.

Question 39

Which of the following reactions is performed by yeast in wine- making?

A) malic acid -lactic acid
B) sugar -CO₂ + H₂O
C) ethanol -acetic acid
D) carbon dioxide -sucrose
E) sugar -ethanol

Question 40

All of the following are true of irradiation methods used for food preservation and sterilization EXCEPT

A) they greatly reduce the number of pathogens present in meats and poultry.
B) residual radioactivity is left behind on many foods.
C) they prolong shelf- life of fruits and vegetables.
D) ionizing radiation such as X rays or gamma rays is used.
E) they are used for the sterilization of many spices.

Question 41

Vessels used for industrial fermentation reactions are known as bioreactors. Explain the difference between batch production and continuous flow production using a bioreactor.

Question 42

High- pressure processing of foods such as deli meats and precooked chicken strips targets pathogens such as C. botulinum.

Question 43

Mesophilic bacteria grow best at temperatures of 60°C.

Question 44

A large industry exists based on the synthesis of amino acids by microorganisms.

Question 45

Industrial canning is achieved using a pressure cooker which operates in a manner similar to an autoclave.

Question 46

Explain how ionizing radiation can be used to preserve foods. Discuss its advantage over canning as a method of preservation.

Question 47

Discuss the production of four different foods that require microbial fermentation in their products. In your discussion, name the specific microorganisms used and describe the fermentation by- product(s) needed for the production of each food item.

Question 48

If an industrial microbiologist works with Thiobacillus ferrooxidans, he is likely to be involved in copper mining.

Question 49

Radiation works to preserve foods through

A) creation of an anaerobic environment and high heat.
B) lethal mutation of bacterial DNA.
C) creation of an anaerobic environment.
D) exposure to high heat.
E) increasing pH.

Question 50

All of the following are industrial products produced by microbes EXCEPT

A) vitamin B12 and riboflavin.
B) uranium.
C) antibiotics.
D) industrial enzymes.
E) amino acids in food supplements.

Question 51

Vitamins A, B₁₂, and E are commonly produced by microorganisms.

Question 52

The longer interior- ripened cheeses are permitted to ripen, the milder the taste of the cheese.

Question 53

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

A) flat sour spoilage.
B) thermophilic anaerobic spoilage.
C) putrefactive anaerobic spoilage.
D) caused by acid- tolerant fungi.
E) spoilage by mesophilic bacteria.

Question 54

The production of vinegar relies on the microbial oxidation of ethanol to acetic acid.

Question 55

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 56

The blue- green clumps observed in Roquefort cheese are a result of mold growth.

Question 57

Which of the following microbes produces a natural biopesticide?

A) Saccharomyces cerevisiae
B) Thiobacillus ferroxidans
C) Lactobacillus buggaricus
D) Bacillus thuringiensis
E) Penicillium chryssogenum

Question 58

Rhizobium and Bradyrhizobium are mixed with peat moss to increase nitrogen fixation.