Deck 16: Food and Industrial Microbiology

Question 1

Alkaline fermentations raise pH through the catabolism of

A) lipids.
B) proteins.
C) sugars.
D) nucleic acids.
E) starches.

Answer 1

B

Question 2

Few bacteria are edible as isolated organisms because of their high content of

A) proteins.
B) nucleic acids.
C) sugars.
D) carbohydrates.
E) lipids.

Answer 2

B

Question 3

Which of the following is the source of alginate, an important food additive?

A) kelp
B) the yeast Saccharomyces
C) shiitake
D) Agaricus bisporus
E) enoki

Answer 3

A

Question 4

Which of the following microbes is responsible for the flavor of Camembert cheese?

A) lactic acid bacteria
B) Propionibacterium
C) Saccharomyces
D) Penicillium
E) Aspergillus

Question 5

Which of the following is classified as a form of single-celled protein?

A) Porphyra
B) Lentinula
C) Spirulina
D) Rhizopus
E) Macrocystis

Question 6

In the process of ________, NO standard starter culture is available.

A) sourdough bread making
B) yogurt making
C) chocolate production
D) cheese making
E) beer making

Question 7

Which of the following contains protein as high as 25% dry weight and are an excellent source of all the essential dietary amino acids?

A) algae
B) bacteria
C) mushrooms
D) yeast cells
E) plants

Question 8

The ________ of milk proteins results in the formation of curds.

A) filtration
B) lyophilization
C) pasteurization
D) coagulation
E) radiation

Question 9

What proportion of known species of mushrooms are poisonous?

A) one-half
B) one-quarter
C) 10%
D) 5%
E) 1%

Question 10

Within a mound of cocoa beans, ________ generates heat so that the mound temperature increases up to 50°C.

A) indigenous fungi
B) aerobic acetic acid bacteria
C) Candida and Kloeckera yeasts
D) Saccharomyces and other yeasts
E) Lactobacillus species

Question 11

Nori used as a sushi wrap is produced by growing Porphyra, a ________, in tanks.

A) green alga
B) red alga
C) brown alga
D) fungus
E) cyanobacterium

Question 12

The flavors of ________ are generated by side products of fermentation, such as flavorful alcohols, esters, and sulfur compounds.

A) cheese
B) yogurt
C) kimchi
D) natto
E) sauerkraut

Question 13

Sauerkraut is primarily fermented with the bacterium ________ that uses a ________ type of fermentation.

A) Lactobacillus; heterolactic
B) Lactobacillus; homolactic
C) Leuconostoc; heterolactic
D) Leuconostoc; homolactic
E) Propionibacterium; heterolactic

Question 14

What are the three stages in the fermentation of cocoa beans for chocolate (in order)?

A) 1) Bacillus, 2) lactic acid bacteria, 3) yeasts
B) 1) acetic acid bacteria, 2) yeasts, 3) lactic acid bacteria
C) 1) yeasts, 2) lactic acid bacteria, 3) acetic acid bacteria
D) 1) Leuconostoc, 2) Bacillus, 3) Rhizopus
E) 1) Leuconostoc, 2) Bacillus, 3) yeasts

Question 15

Tempeh, a staple food of Indonesia, is produced by an initial fermentation of soybeans with ________, followed by ________.

A) lactic acid bacteria; Aspergillus oryzae
B) lactic acid bacteria; Rhizopus oligosporus
C) Propionibacterium spp.; Aspergillus oryzae
D) Propionibacterium spp.; Leuconostoc mesenteroides
E) Propionibacterium spp.; Rhizopus oligosporus

Question 16

What are two types of mushrooms that are both cultures of Agaricus bisporus that are harvested at different stages?

A) portobello and shiitake
B) morel and truffle
C) button and portobello
D) shiitake and truffle
E) nori and morel

Question 17

Which of the following food products is NOT produced by alkaline fermentation?

A) natto
B) kimchi
C) dawadawa
D) pidan
E) thousand-year eggs

Question 18

Mold ripening refers to the secondary ________ stage of cheese production.

A) respiration
B) curd
C) contamination
D) bacterial
E) fermentation

Question 19

Miso is a fermented Japanese condiment made primarily from ________, which is salted and fermented with ________ for two months.

A) cabbage; Leuconostoc
B) rice; Leuconostoc
C) cabbage; Bacillus
D) cabbage; Aspergillus oryzae
E) ground soy and rice; Aspergillus oryzae

Question 20

Production of traditionally fermented foods typically relies on ________ microbiota, whereas commercial fermentation generally relies on ________.

A) soil; edible
B) edible; indigenous
C) airborne; indigenous
D) indigenous; starter cultures
E) indigenous; chemicals

Question 21

Which of the following organisms or processes is NOT involved in the chocolate-making process?

A) yeasts
B) lactic acid bacteria
C) acetic acid bacteria
D) thermophilic bacteria
E) both anaerobic and aerobic processes

Question 22

In beer making, enzymatic activities during germination of barley produce the ________ used for fermentation.

A) ethanol
B) maltose
C) malic acid
D) lactic acid
E) 2-oxo acids

Question 23

The most common food-borne cause of death in the United States is

A) norovirus.
B) Salmonella enterica.
C) Campylobacter sp.
D) Clostridium botulinum.
E) Escherichia coli O157:H7.

Question 24

Ethanolic fermentation of ________ was important to early civilizations because it provided a drink free of waterborne pathogens.

A) roots
B) flowers and leaves
C) leaves
D) grain and fruit
E) stems and leaves

Question 25

The purpose of malolactic fermentation in the second stage of production of some wines is to

A) impart wines with a fruity flavor.
B) eliminate phenolics.
C) eliminate acidity caused by malic acid.
D) destroy acetaldehyde (off-flavor).
E) produce esters (desirable flavors).

Question 26

The virulence genes of Salmonella are found in a genomic region referred to as pathogenicity

A) islands.
B) plasmids.
C) groups.
D) operons.
E) hotspots.

Question 27

Food spoilage can be brought about by all the following, EXCEPT

A) chemical reactions with the environment, such as oxidation of lipids.
B) meat tenderization.
C) putrefaction of food by decomposition of protein and amino acids.
D) action of bacterial fermentations to make food sours.
E) conversion of sugar into starch in freshly picked corn.

Question 28

Escherichia coli O157:H7 was first observed in fast-food hamburger meat. More recently, it has been associated with contamination of spinach and other vegetables. How did the spread of this strain from meat to vegetables happen?

A) It picked up genes for plant virulence.
B) Strain O157:H7 can grow as a plant endophyte.
C) It has become a psychrotroph and can grow in refrigerated foods.
D) It produces toxins that can survive on plant material.
E) This bacterial strain has lost genes needed to grow in meat.

Question 29

Which of the following aids microbial growth?

A) drying
B) radiation
C) addition of spices
D) refrigeration
E) warming the food to body temperature

Question 30

Another term for freeze-drying is

A) radiation.
B) dehydration.
C) filtration.
D) pasteurization.
E) lyophilization.

Question 31

Cinnamon and cloves contain a ________ derivative that is a potent microbial inhibitor.

A) lipid
B) nucleotide
C) benzene
D) bacterial
E) fungal

Question 32

Wines are produced from fermentation of crushed grapes. What causes the either white or red color of wine?

A) In white wine production, additional aging removes pigments by oxidation.
B) To produce white wine, red pigments are chemically removed prior to bottling.
C) Additional fermentation degrades the red pigments of red wine, rendering it white.
D) To make white wine, grape skins are removed (pressing) before inoculation with yeast.
E) Ultracentrifugation of red wine removes pigments, leading to rosé or white wines.

Question 33

Until the recent invention of ________, all foods contained live microbes.

A) steam-pressure sterilization
B) irradiation
C) lyophilization
D) freezing
E) refrigeration

Question 34

Alcohol dehydrogenase in the ________ detoxifies alcohol produced in the intestines.

A) lungs
B) liver
C) mouth
D) pancreas
E) spleen

Question 35

Listeria is a(n) ________ organism, which means that it readily grows at refrigeration temperatures.

A) neutrophilic
B) acidophilic
C) mesophilic
D) autotrophic
E) psychrotrophic

Question 36

Brewer's yeast, Saccharomyces cerevisiae, conducts ________ fermentation of maltose, a ________, which is produced by the action of amylases on starch.

A) ethanolic; pectin
B) lactic acid; lactone
C) ethanolic; disaccharide
D) mixed; fructose
E) ethanolic; monosaccharide

Question 37

Leavening of commercial bread dough is brought about by CO₂ from ________ fermentation by ________.

A) mixed; Propionibacterium species
B) ethanolic; Oenococcus
C) alkaline; Bacillus species
D) ethanolic; Saccharomyces cerevisiae
E) acid; lactic acid bacteria

Question 38

Which of the following products of beer making and winemaking result in off-flavors?

A) esters
B) ethanol
C) acetaldehyde
D) long-chain alcohols
E) amino acids

Question 39

The filtered mash in beer making is referred to as

A) hops.
B) barley.
C) yeast extract.
D) malt.
E) wort.

Question 40

A modest level of ethanol enters the human circulation naturally from ________, equivalent to a fraction of a drink per day.

A) intestinal microbiota byproducts
B) food
C) drink
D) cell metabolism
E) the environment

Question 41

The ________ gene products stimulate plasmid transfer from Agrobacterium to the host plant.

A) Ti
B) promoter
C) recombinant
D) auxin synthesis
E) vir

Question 42

Briefly describe the cheese-making process. Use the figure below to explain why different cheeses have different flavors.

Question 43

All of the following are examples of the use of alginates derived from Macrocystis pyrifera, EXCEPT

A) fermentation substrate for cheese production.
B) textile printing agent.
C) modeling material for dental applications.
D) skin-safe life casting.
E) ice cream thickener.

Question 44

Use the figure below to describe four types of fermentation used in food preparation. Make sure to indicate what the Roman numerals indicate. Give an example of a product that is made from each type of fermentation.

Question 45

An acid or base serves as an effective preservative because

A) pH change is likely to be reversed.
B) pH change is unlikely to be reversed.
C) animals and plants grow at high pH.
D) animals and plants grow at low pH.
E) animals and plants grow at extreme pH.

Question 46

Which of the following is NOT an example of a microbial enzyme used in industrial or commercial applications?

A) cellulase-improvement of fabric's appearance
B) asparaginase-avoidance of acrylamide production
C) rennin-cheese production
D) lipase B-active in a wide range of temperatures
E) protease-removal of food stains on clothes

Question 47

How is injera produced and why is it nutritionally better than quick-rising wheat breads?

Question 48

Use the figure below and find the INCORRECT statement regarding the development process for the antituberculosis compound SQ109.

A) The question mark (?) indicates to the general formula for 62,238 compounds made in a combinatorial library of ethambutol derivatives.
B) The yellow highlighted portion of the molecules correspond to the ethambutol diamine core.
C) All 63,238 diamine molecules in the combinatorial library were tested in tissue culture, activity in infected macrophages and in live animals.
D) Out of 69 compounds showing the best activity against Mycobacterium tuberculosis, SQ109 had the greatest efficacy and fewer side effects.
E) Out of 63,238 diamine molecules in the combinatorial library, 2,796 showed activity against Mycobacterium tuberculosis in vitro.

Question 49

The following are desirable characteristics of an industrial strain, EXCEPT

A) efficient gene transfer system.
B) susceptibility to large DNA rearrangements.
C) inexpensive growth and maintenance.
D) safe, non-pathogenic.
E) easy harvesting of product.

Question 50

What are some of the purposes of food fermentation? Why have humans been making fermented foods for so long?

Question 51

Actinovate is a preparation of Streptomyces lydicus, an example of a microbe as product. Which of the following is NOT correct regarding Actinovate?

A) It is used to suppress fungi causing seedling damping-off.
B) Streptomyces lydicus produces a protein that is toxic to the larvae of several insect pests.
C) It fends off fungal pathogens on leaves.
D) Streptomyces lydicus feeds off plant exudates while secreting antimicrobial substances.
E) It is used to eliminate root rot.

Question 52

An attribute of an industrial microbial strain is

A) genetic stability and manipulation.
B) expensive growth requirements.
C) a low level of product expression.
D) pathogenic strains.
E) the cell is not easily breakable to liberate product.

Question 53

What type of processing refers to steps in product recovery and purification?

A) pasteurization
B) finishing
C) upstream
D) downstream
E) lyophilization

Question 54

Microorganisms are used in the production of many small molecules, such as amino acids, vitamins, and medicines. Which of the following is NOT produced by a bacterium?

A) steroids
B) L-lysine
C) vitamin B12
D) penicillin
E) tetracycline

Question 55

Recombinant Escherichia coli is used in the production of the following EXCEPT

A) interferon.
B) CC10 lung development protein.
C) human growth hormone.
D) insulin.
E) antibodies.

Question 56

Describe how the transportation of milk products by herders led to the formation of cheeses.

Question 57

The search for organisms with potential commercial application is called

A) biopanning.
B) bioprospecting.
C) recombinant DNA technology.
D) deep sequencing.
E) metagenomics.

Question 58

Another term for food contamination is

A) rancid.
B) putrefacation
C) food poisoning.
D) food spoilage.
E) putrefied.

Question 59

Why is it better nutritionally to ferment soybeans than to consume them without fermenting?

Question 60

Bacteria generally can't be eaten as isolated organisms. Why is Spirulina an exception? What is Spirulina and what are its health benefits?

Question 61

Why is Agrobacterium used in genetic engineering of plants? Briefly explain the Agrobacterium expression system.

Question 62

Describe the primary and secondary fermentations involved in winemaking.

Question 63

Describe several physical means of food preservation.

Question 64

Explain the difference between food spoilage and food poisoning.

Question 65

The graph below shows an experiment in which growth of aerobic bacteria in ground beef (CFUs/g) was measured at different refrigeration temperatures. Interpret the graph and explain what the dotted line represents.

Question 66

Describe some of the characteristics that industrial strains of microbes must possess.

Question 67

In the figure below, identify the carbohydrate substrate for fermentation in the production of beer and wine. Compare and contrast the desirable flavors and off-flavors that may come about during ethanolic fermentation in both cases.

Question 68

With respect to an industrial process, what are upstream and downstream processing methods, and how do they differ?

Question 69

The figure below represents microbial growth (CFUs/mL) during the very early stages of chocolate production. Use the numbers to describe the microbial succession involved in the complex fermentation of cocoa pulp.

Question 70

What makes a company dealing with industrial microbiology a success?

Question 71

The strain Escherichia coli O157:H7 is pathogenic for humans. It was first identified in ground beef. What does an infection with it cause and do to humans? Why do you suppose infections are more prevalent in ground meat than on a steak?

Question 72

What categories of foods may be spoiled by psychrotrophs? Why are these organisms a problem with fish?

Question 73

Use the figure below to discuss how molecular tools are used in the investigation of pathogen-contaminated food. What does the figure represent? What is the overall conclusion of the analysis?