Deck 16: Food and Industrial Microbiology

Question 1

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

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

Answer 1

E

Question 2

__________ within the mound of cocoa beans generate(s) heat so that the mound temperature increases up to 50 C.

A) Indigenous fungi
B) Oxidative respiration thermophiles
C) Fermentation
D) Anaerobic respiration
E) Lactic acid bacteria

Answer 2

B

Question 3

Tempeh is produced by fermentation of soybeans with ________, initially followed by __________.

A) lactic acid bacteria; Aspergillus
B) lactic acid bacteria; Rhizopus
C) Propionibacterium; Aspergillus
D) Propionibacterium; Leuconostoc
E) Propionibacterium; Rhizopus

Answer 3

B

Question 4

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

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

Question 5

Which of the following is a characteristic of fungal fruiting bodies?

A) They ferment and spoil fruits.
B) They are poisonous to eat.
C) They produce antibiotics.
D) They generate spores.
E) They transfer genes to plants.

Question 6

Few bacteria are edible as isolated organisms because they have a high concentration of:

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

Question 7

Three stages in the fermentation of cocoa beans for chocolate are (in order):

A) Bacillus, lactic acid bacteria, yeasts
B) acetic acid bacteria, yeasts, lactic acid bacteria
C) yeasts, lactic acid bacteria, acetic acid bacteria
D) Leuconostoc, Bacillus, Rhizopus
E) Leuconostoc, Bacillus, yeast

Question 8

Production of traditionally fermented foods typically relies on __________ flora, whereas commercial fermentation generally relies on __________.

A) starter cultures; normal
B) normal; indigenous
C) starter cultures; indigenous
D) indigenous; starter cultures
E) indigenous; chemicals

Question 9

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 10

NO starter culture is available for which of the following processes?

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

Question 11

Which of the following mushrooms is NOT grown on logs or wooden blocks?

A) portobello
B) black forest
C) shiitake
D) oyster
E) enoki

Question 12

__________ mushrooms and __________ mushrooms are both cultures of Agaricus bisporus that are harvested at different stages.

A) Portobello; shiitake
B) Morel; truffle
C) Button; portobello
D) Shiitake; truffle
E) Nori; morel

Question 13

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

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

Question 14

__________ flavors are generated by side products of fermentation, such as esters.

A) Cheese
B) Yogurt
C) Kimchi
D) Natto
E) Sauerkraut

Question 15

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

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

Question 16

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

A) green algae
B) red algae
C) brown algae
D) fungus
E) bacterium

Question 17

Sauerkraut is fermented with a __________ type of fermentation using the bacterium __________.

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

Question 18

Natto is a fermented Japanese food made primarily from __________ and fermented with __________.

A) cabbage; Leuconostoc
B) soybean; Leuconostoc
C) cabbage; Bacillus
D) soybean; Bacillus
E) cabbage; lactic acid bacteria

Question 19

__________ are an excellent source of all the essential dietary amino acids.

A) Algae
B) Bacteria
C) Mushrooms
D) Yeast
E) Cheeses

Question 20

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 21

Which of the following terms refers to the sediment of grape and yeast materials produced during wine production?

A) curd
B) hops
C) wort
D) lees
E) tannins

Question 22

Refrigeration does NOT stop food decomposition because __________ organisms are capable of growth at these temperatures.

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

Question 23

Which of the following is the most common cause of food-borne deaths in the United States?

A) norovirus
B) Salmonella
C) Campylobacter
D) Clostridium botulinum
E) coli O157:H7

Question 24

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

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

Question 25

In beer making, germination of barley followed by its enzymatic activity produces the __________ used for fermentation.

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

Question 26

Alkaline fermentations raise pH through the catabolism of:

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

Question 27

Alcohol dehydrogenase is produced in the __________ to detoxify alcohol produced in the intestines.

A) intestines
B) liver
C) mouth
D) pancreas
E) fermentation

Question 28

Malolactic fermentation is a step in the production of what food?

A) yogurt
B) beer
C) wine
D) chocolate
E) soy sauce

Question 29

Leavening of commercial bread dough is brought about by:

A) CO₂ from injera fermentation
B) CO₂ from ethanolic fermentation of lactic acid bacteria
C) CO₂ from aerobic metabolism of yeasts
D) CO₂ from ethanolic fermentation by Saccharomyces cerevisiae
E) CO₂ from Candida

Question 30

Spores produced by Clostridium botulinum, which endanger infants less than 2 years of age, are often found in which of the following foods?

A) yogurt
B) kefir
C) honey
D) cheeses
E) eggs

Question 31

Which of the following does NOT aid in the retardation of microbial growth?

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

Question 32

__________ fermentation of grain or fruit was important to early civilizations because it provided a drink free of waterborne pathogens.

A) Lactic acid
B) Bacterial
C) Acetic acid
D) Ethanolic
E) Maltose

Question 33

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

A) intestinal flora
B) food
C) drink
D) human metabolism
E) aerobic respiration

Question 34

__________ is another term for freeze-drying.

A) Radiation
B) Dehydration
C) Filtration
D) Pasteurization
E) Lyophilization

Question 35

Brewer's yeast, Saccharomyces cerevisiae, conducts __________ fermentation of maltose produced by the hydrolysis of __________.

A) ethanolic; sugar
B) lactic acid; starch
C) ethanolic; starch
D) acetic acid; barley
E) barley; ethanol

Question 36

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

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

Question 37

The virulence genes of Salmonella are found in what are referred to as pathogenicity:

A) islands
B) sectors
C) regions
D) operons
E) areas

Question 38

Which of the following growth conditions limits abiotic oxidation as well as microbial growth?

A) refrigeration
B) pasteurization
C) ionizing radiation
D) increased oxygen
E) increased carbon dioxide

Question 39

The filtered mash in beer making is referred to as:

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

Question 40

Which of the following methods is NOT used in studying food-borne illnesses?

A) reporting cases to the CDC
B) when a food is identified as a cause of an illness, tracing it to a factory or farm
C) electron microscopy of the foods to find the pathogen
D) molecular tests on isolated bacteria thought to be the cause
E) comparing food intake histories of ill people to look for matches

Question 41

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

Question 42

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

Question 43

What is pidan and how is it made?

Question 44

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

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

Question 45

__________ processing refers to steps in product recovery and purification.

A) Pasteurization
B) Finishing
C) Upstream
D) Downstream
E) Lyophilization

Question 46

Cheese is less susceptible to spoiling than other dairy products because:

A) amines produced by the degradation of protein prevent the growth of pathogens
B) its solid structure and lower water activity minimizes growth of pathogens
C) molds growing on the surface promote good health
D) Aspergillus produces toxins that kill pathogens
E) if it spoils, it becomes a new kind of cheese

Question 47

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

A) Ti
B) promoter
C) recombinant
D) host
E) vir

Question 48

Chemical means of preserving food include all of the following EXCEPT:

A) lowering the pH below 5
B) addition of nitrosamines
C) use of organic acids, such as sorbic acid, as preservatives
D) use of esters as antimicrobials
E) use of salt

Question 49

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

Question 50

List four different types of fermentation, their end products, and an example of a product that is made from each type.

Question 51

Briefly describe the cheese-making process. Why do different cheeses have different flavors?

Question 52

Cinnamon and cloves contain a(n) __________ derivative that is a potent microbial inhibitor.

A) acid
B) alkaline
C) benzene
D) bacterial
E) fungal

Question 53

Recombinant E. coli is used in the production of all of the following EXCEPT:

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

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

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

Question 56

Food spoilage can be brought about by all of the following EXCEPT:

A) chemical reactions with the environment, such as oxidation of lipids
B) enzymatic actions, such as proteolysis of meats to tenderize them
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 57

Why are wines different colors if they are all made from grapes?

Question 58

E. 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 this spread from meat to vegetables happen?

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

Question 59

Why aren't bacteria usually edible as isolated organisms? What problems could occur if a person ate large quantities of bacteria?

Question 60

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

Question 61

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

Question 62

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

Question 63

The human pathogen E. coli O157:H7 was first identified in ground beef. How did it get there, and 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 64

Compare and contrast the desirable flavors and off-flavors that may come about during the ethanolic fermentation to make beer and wine.

Question 65

Why does bread sometimes turn red? Describe the "miracle" with which this has been associated.

Question 66

Describe several physical means of food preservation.

Question 67

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

Question 68

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

Question 69

What makes a company dealing with industrial microbiology a success?

Question 70

Compare and contrast the primary and secondary fermentations involved in winemaking.