Microbiology with Diseases by Body System, 5e (Bauman)
Chapter 25 Applied and Industrial Microbiology
25.1 Multiple Choice Questions
1) Control of the fermentation of foods to produce the desired product commonly involves
A) careful choice of foodstuffs.
B) pretreating the food by boiling.
C) adding required nutrients for microbial growth.
D) use of a starter culture.
E) both pretreating the food by boiling and adding required nutrients for microbial growth.
2) A researcher studying the impact of agricultural pesticides on native plants discovers a
bacterium capable of degrading small amounts of a specific pesticide. The researcher then
modifies the bacterial species in the lab to increase the rate of pesticide degradation. This
research represents
A) applied microbiology.
B) environmental microbiology.
C) food microbiology.
D) both food microbiology and environmental microbiology.
E) both applied microbiology and environmental microbiology.
3) Sourdough bread is produced using
A) yeast.
B) Aspergillus oryzae.
C) lactic acid bacteria.
D) both yeast and lactic acid bacteria.
E) both Aspergillus oryzae and lactic acid bacteria.
4) Why are “fortified” foods more likely to spoil than are unfortified foods?
A) The addition of vitamins or minerals makes the food more nutritious for microbes as well as
humans.
B) Vitamins are added to “fortified” foods by adding the microbes that produce the vitamins to
the food item.
C) Every step of modification or manipulation of food increases the chance for contamination.
D) The addition of nutrients creates an osmotic environment suitable for a wide range of
microbes.
E) The vitamins require a neutral pH environment, which is suitable for many microbes.
5) Which of the following is a lactic acid bacterium used in the production of food?
A) Aspergillus oryzae
B) Gluconobacter
C) Leuconostoc
D) Penicillium
E) Saccharomyces cerevisiae
6) The fermentation product known as silage is
A) a step in the production of brandy.
B) a means of food preservation.
C) a means of making plant materials more appealing to livestock.
D) a meat product.
E) made from milk.
7) Sulfur dioxide is added to “must” in the production of wine to
A) improve the flavor.
B) allow more control over the fermentation process.
C) provide a necessary nutrient for the fermentation process.
D) prevent tannins from leaching out of wood into the fermenting wine.
E) both enhance flavor and promote fermentation.
8) Why is the pasta you buy from the grocery store shelf considered a nonperishable food?
A) It has a low nutritional content.
B) It was sterilized during preparation.
C) The low moisture content prevents microbial growth.
D) Various preservative chemicals are added.
E) Microbes present in the pasta inhibit the growth of harmful microbes.
9) Which of the following beverages is made from fermented fruit?
A) beer
B) brandy
C) sake
D) vodka
E) both beer and vodka
10) Which of the following results when ethanol is allowed to oxidize to acetic acid following
the fermentation of fruit, grain, or vegetables?
A) beer
B) wine
C) champagne
D) vinegar
E) malt
11) Which of the following items that are commonly added during food preparation can be
considered a preservative?
A) apple juice
B) meat broth
C) garlic
D) yeast
E) whey
12) An intrinsic factor of food that can determine whether spoilage occurs is
A) the degree of processing.
B) the amount of preservatives added.
C) the storage temperature.
D) the water content.
E) storage packaging.
13) Pickling is an effective means of food preservation involving
A) increasing oxygen content.
B) increasing salt concentration.
C) reducing pH.
D) reducing oxygen content.
E) increasing salt concentration or reducing pH or both.
14) Which of the following is used in both food production and industrial fermentation?
A) Bacillus thuringiensis
B) Escherichia coli
C) Listeria monocytogenes
D) Pseudomonas syringae
E) Saccharomyces cerevisiae
15) Sugar and salt act as preservatives by
A) inhibiting bacterial enzymes.
B) producing oils that inhibit bacterial growth.
C) inhibiting DNA replication.
D) drawing water out of microbes.
E) killing endospores.
16) Which of the following methods of preserving food sterilizes it?
A) canning
B) pasteurization
C) drying
D) gamma radiation
E) lyophilization
17) What is the significance of the industrial practice of waiting for cultures to enter the
stationary phase of growth before harvest?
A) The cells are at peak metabolic activity.
B) Secondary metabolites are often the desired product, and are only produced in stationary
phase.
C) The desired primary metabolites are produced in stationary phase.
D) Potential toxins from log phase growth have been depleted.
E) An optimal combination of primary and secondary metabolites is being produced.
18) Undercooked shellfish contaminated with ________ can lead to foodborne illness.
A) Toxoplasma gondii
B) Campylobacter jejuni
C) Listeria monocytogenes
D) Yersinia enterocolitica
E) Vibrio vulnificus
19) Food contaminated with ________ may contain a potent neurotoxin.
A) Salmonella spp.
B) Shigella spp.
C) Clostridium botulinum
D) Escherichia coli
E) Listeria monocytogenes
20) Which of the following pairs of industrial microbial products and their uses is
MISMATCHED?
A) streptokinase; dissolving blood clots
B) indigo; cloth dye
C) citric acid; antioxidant in food
D) gluconic acid; release of cellulose from flax to make linen
E) phenylalanine; the sweetener aspartame
21) Which of these microbial products is needed to produce “gasohol”?
A) citric acid
B) methanol
C) ethanol
D) hyaluronidase
E) aspartame
22) What was the first substance produced by microorganisms to be used pharmaceutically?
A) penicillin
B) streptokinase
C) taxol
D) human insulin
E) interferons
23) Industrial fermentation and fermentation in food production
A) are both processes in which sugars are oxidized to alcohols or acids.
B) are processes in which sugar or protein is oxidized to produce alcohols or acids.
C) use entirely different microorganisms.
D) use entirely different starting material.
E) make use of the same microorganisms.
24) During treatment of water to make it potable, about 90% of the microbes are removed
A) by preliminary fermentation.
B) in the sedimentation step.
C) by treatment with biosensors.
D) by treatment with chlorine or ozone.
E) in the filtration step.
25) Potable water is water that
A) is considered safe to drink because it is completely sterile.
B) contains biosensors.
C) contains a dangerous number of microorganisms.
D) is transferred from one place to another.
E) contains low amounts of microorganisms and is considered safe to drink.
26) Municipal chlorinated water contains
A) no viruses.
B) no bacteria at all.
C) no endospores.
D) no cysts.
E) a decreased microbial load.
27) Which of the following microorganisms is the most commonly used indicator organism for
water quality testing?
A) Escherichia coli
B) Salmonella spp.
C) Shigella spp.
D) Campylobacter jejuni
E) Hepatitis A virus
28) Which of the following statements concerning the biochemical oxygen demand (BOD) is
CORRECT?
A) It is a measure of the amount of oxygen in water.
B) It is proportional to how potable water is.
C) It is used as a bioreceptor index.
D) It is a measurement of the amount of oxygen that aerobic bacteria require to decompose
organic wastes in water.
E) It is a filter system to purify drinking water.
29) Which of the following is produced by fermentation?
A) beef jerky
B) pasteurized milk
C) pepperoni
D) mozzarella cheese
E) pepperoni and mozzarella cheese
30) Which of the following is the CORRECT sequence of steps for beer preparation?
A) mashing, malting, fermentation, clarification, aging
B) malting, mashing, adding hops, fermentation, aging
C) mashing, malting, fermenting, aging, clarification
D) malting, fermenting, adding hops, clarification, aging
31) Which of the following additives help preserve food as well as enhancing flavor?
A) cinnamon
B) garlic
C) salt
D) salt and pepper
E) cinnamon, garlic, and salt
32) Which of the following microorganisms associated with food poisoning thrives in cold
storage?
A) Salmonella spp.
B) Shigella spp.
C) Clostridium botulinum
D) Escherichia coli
E) Listeria monocytogenes
33) Secondary metabolites are often useful, and are obtained by
A) harvesting a culture during log phase.
B) allowing a culture to enter stationary phase.
C) growing a culture at sub-optimal temperature.
D) adding chemicals that alter metabolic pathways.
E) using continuous flow culturing.
34) A patient is brought to the emergency room in a comatose state. The family reports he had
complained of nausea and a bad headache in the past couple of days. They also report they had
engaged in their normal summer activities: picnicking, fishing and swimming at the lake near
their home. His fever is high, and while in the ER, he has a seizure. Which of the following is
likely to be responsible for his symptoms?
A) Entamoeba histolytica
B) Giardia intestinalis
C) Gonyaulax
D) Naegleria fowleri
E) Toxoplasma gondii
35) Which of the following is a waterborne pathogen that causes severe diarrhea?
A) Entamoeba histolytica
B) Naegleria fowleri
C) Campylobacter jejuni
D) Toxoplasma gondii
E) Gonyaulax species
36) Which of the following is a microbial product used to reduce crop damage?
A) Bt toxin
B) saxitoxin
C) ice-minus
D) both Bt toxin and ice-minus
E) both Bt toxin and saxitoxin
37) Which of the following may result from eating shellfish?
A) botulism
B) norovirus infection
C) polio
D) salmonellosis
E) paralysis
38) Microbial proteases are used
A) in the production of linen.
B) as preservatives.
C) in spot removers.
D) as a component of fabric dyes.
E) to biodegrade plastics.
39) Which of the following is an application of proteases?
A) cheese
B) indigo
C) meat tenderizer
D) vodka
E) wine
40) Streptokinase is useful for which of the following?
A) producing antibiotics
B) cheese production
C) biosensors
D) dissolving blood clots
E) insecticide
41) A common source of antibiotics is
A) Acetobacter.
B) Aspergillus oryzae and Lactobacillus.
C) Lactoccocus cremoris.
D) Streptococcus thermophilus.
E) Streptomyces.
42) Which of the following may result from eating tuna sashimi (raw fish)?
A) botulism
B) norovirus infection
C) polio
D) salmonellosis
E) saxitoxin intoxication
43) Soy sauce is made using
A) Acetobacter.
B) Aspergillus oryzae and Saccharomyces.
C) Aspergillus oryzae and Lactobacillus.
D) Saccharomyces.
E) Lactoccocus cremoris.
1) Most microbes need an environment that has a water activity of at least 0.90.
2) The starter culture used to make cheese determines the type of cheese produced.
3) Amino acid and vitamin supplements are prepared from extracts of microbial cultures.
4) Pasteurization is a more rigorous process than canning.
5) Cold is preferred for storing food because it retards microbial growth by slowing down
metabolic processes.
6) Canned foods are prepared using the same temperature as is used for autoclaving.
7) Through recombinant DNA technology, many plants now can manufacture their own Bt toxin,
which improves fermentation.
8) Reducing the water content of food is a highly effective way of reducing food spoilage.
9) Food poisoning is often the result of ingesting microbial toxins, not the microbes themselves.
10) Water contamination refers only to the presence of excess or non-endemic microbes.
25.3 Short Answer Questions
1) The definition of (fermentation/cultivation/processing) used by food microbiologists is a
desirable change in food due to microbial activity.
2) Because the same microbes are not always present on food from harvest to harvest,
(fresh/natural/starter) cultures are used in the production of alcoholic beverages.
3) The sour flavor in some fermented foods is usually the result of (acetic/benzoic/lactic) acid
production.
4) The process of preserving foods in brine is called (canning/pickling/salting).
5) Garlic contains an antimicrobial substance called (allicin/penicillin/streptomycin).
6) A few hours after a dinner party, most of the people who attended begin to suffer nausea,
vomiting, and diarrhea. The food at the meal is suspected as the source, although no unusual
microbes are cultured from samples of the food or from stool samples. These observations
suggest they may be suffering from food (infection/intoxication).
7) Brandy is made by the same process as wine, but the alcohol is then concentrated by
(fermentation/distillation/filtration).
8) Freezing food and then using a vacuum to draw off the ice crystals is called
(dehydration/lyophilization/sublimation).
9) Benzoic acid is largely a(n) (antifungal/antiprotozoal/pickling) agent and does not affect the
growth of many bacteria.
10) The protozoan parasite (Gonyaulax/Toxoplasma gondii/Vibrio vulnificus) is acquired by
eating contaminated meat.
11) With the (batch/continuous/static) production technique, organisms are allowed to ferment
their substrate until it is exhausted.
12) Botryococcus braunii is an alga that produces hydrocarbons at (10/20/30) percent of its dry
weight and could be harvested in the future as an alternative fuel.
13) The destruction of (cysts/endospores/viruses) is the goal of industrial canning procedures.
14) The enzyme (amylase/hyaluronidase/lipase) can be used in injected medications to enhance
their rate of absorbance.
15) Water quality can be tested by detection of (E. coli/Cryptosporidium/norovirus) using the
chemical known as MUG.
25.4 Essay Questions
1) Before the discovery of microbes humans had been preserving meat in a variety of ways.
Discuss how these methods might have been discovered.
2) Compare the use of biosensors with traditional methods of determining microbial
contamination.
3) In modern times beer and wine are considered recreational beverages. In the past they were
important staples in the human diet, so much so that their consumption is often remarked upon in
historical documents. Why were they so important?
4) Use of genetically modified crop plants may be crucial to feeding the world’s growing
population. Discuss this statement with regard to BT toxin production in modified crop plants.
5) Compare and contrast the two types of foodborne disease.