Deck 25: Applied Microbiology and Food and Water Safety

Question 1

The mass, controlled culture of microbes to produce desired organic compounds is ______.

A) biosynthesis
B) bioremediation
C) biotechnology
D) fermentation

Answer 1

fermentation

Question 2

The ?rst step in sewage treatment is ______.

A) chlorination
B) sedimentation
C) aeration and settling
D) ?ltration

Answer 2

sedimentation

Question 3

A 100 ml sample of water is ?ltered through a sterile membrane, and the membrane is transferred to a plate of m-Endo agar. Following overnight incubation at 37°C, 57 green metallic colonies appear. The coliform count is _______.

A) acceptable for drinking water and recreational use
B) acceptable for recreational use but too high for drinking water
C) too high for both drinking water and recreational use

Answer 3

acceptable for recreational use but too high for drinking water

Question 4

Which of the following is not true of coliforms?

A) Finding coliforms in water indicates fecal contamination.
B) They include
C) They are gram-negative, lactose-fermenting, and gas-producing.
D) Coliform counts are not speci?c for a particular species of bacteria.
E) coli, Enterobacter, and Giardia.

Question 5

Indicator bacteria for contaminated water are ______.

A) coliforms
B) all bacteria
C) staphylococci
D) Clostridia

Question 6

In the secondary phase of water treatment, organic matter undergoes biodegradation by a diverse mix of bacteria, algae, and protozoa.

Question 7

Which of the following statements regarding waterborne pathogens is incorrect?

A) Waterborne pathogens include bacteria, viruses, and protozoans.
B) Waterborne pathogens are primarily Campylobacter, Salmonella, Shigella, Vibrio, and Mycobacterium.
C) Encysted protozoans can survive in water for long periods without a human host.
D) Microbes can enter surface water through ordinary exposure to air and soil.

Question 8

Primary sewage treatment includes ______.

A) sludge digesting
B) chlorination
C) ?ltration
D) aeration
E) skimming

Question 9

Which chemical is used in both water puri?cation and sewage treatment to provide long-term disinfection?

A) Fluorine
B) Copper sulfate
C) Activated charcoal
D) Chlorine

Question 10

Place the steps of the water puri?cation process in order.

A) Aeration, ?ltration and settling, chemical disinfection, release into a water reservoir
B) Chemical disinfection, aeration, ?ltration and settling, release into a water reservoir
C) Filtration and settling, chemical disinfection, aeration, release into a water reservoir
D) Release into a water reservoir, aeration, ?ltration and settling, chemical disinfection

Question 11

The difference between water puri?cation and sewage treatment is _______.

A) the types of microorganisms used for the treatment
B) whether the water source is residential or commercial
C) the amount of air pumped into the water for treatment
D) there is microbial degradation in sewage treatment, but not in water puri?cation

Question 12

Potable water must be ______.

A) absolutely clear
B) sterile
C) free of all elements
D) free of pathogens

Question 13

Sewage sludge, the solid that remains after aerobic decomposition, makes a useful fertilizer because _______.

A) it contains signi?cant energy in the form of methane
B) it is rich in carbon and nitrogen
C) it has been treated to remove microbes and will not be a source of pathogens
D) it is rich in nitrogen, phosphorus, and potassium

Question 14

Sewage treatment processes result in the production of ______, which can be used to make electricity.

A) carbohydrates
B) methane
C) nitrates
D) hydrogen gas

Question 15

The study of the practical use of microbes in various industries and technologies is ______.

A) applied microbiology
B) microbial ecology
C) biotechnology
D) bioremediation

Question 16

Biotechnology includes all of the following except _______.

A) modifying antibiotics with different chemical functional groups to increase their potency
B) using genetically-modi?ed
C) using bacterial antifreeze proteins to protect crops from lethal frosts
D) using bacterial insecticidal proteins as a means to combat mosquitoes as disease vectors
E) coli as a tool to detect cancer

Question 17

Which of the following statements regarding coliform bacteria is correct?

A) Coliforms derive from the intestinal tract and therefore indicate fecal contamination.
B) The presence of Klebsiella is a strong indicator of fecal contamination.
C) Coliforms from the human and bovine GI tracts differ, so identifying the speci?c microbe will indicate the source of contamination.
D) Petri dishes used to enumerate coliforms are best incubated at 45-48°C.

Question 18

The most prominent water-borne pathogens of recent times include all of the following except ______.

A) Salmonella
B) Staphylococcus
C) Norwalk viruses
D) Cryptosporidium

Question 19

Methane can be produced from agricultural or industrial products by ______.

A) fermentation
B) oxidation of nitrogen gas
C) anaerobic respiration
D) glycolysis

Question 20

The ?nal treatment of sewage before release into the environment is ______.

A) chlorination
B) aeration
C) ?ltration
D) skimming
E) sludge digesting

Question 21

A pure or mixed sample of known microbes added to food is a/an ______.

A) aerator
B) leavening
C) fermenter
D) starter culture
E) ?avor inducer

Question 22

The basis of the membrane ?lter technique is that _______.

A) bacteria are larger than the holes in the ?lter
B) the membrane has an antibiotic that kills bacteria in the water
C) bacteria are small enough to go right through the ?lter
D) the dilutions of the sample allow a total bacterial count when plated out using pour or spread plates

Question 23

The source of wild yeasts carried in a bio?lm on grapes is the ______.

A) bloom
B) malt
C) must
D) wort

Question 24

You made your ?rst batch (ever) of wine about 6 weeks ago. You used a new plastic garbage can, covered with plastic wrap over the top, for the process. Now you get a cup of it out of the container only to ?nd no alcohol--just really bad juice. What went wrong?

A) The plastic of the container released chemicals that killed the yeasts.
B) The yeasts were not under anaerobic conditions.
C) You bought the wrong yeast species at the store.
D) Your yeasts mutated into non-alcohol producing organisms.

Question 25

Which step in making beer involves sprouting and softening the barley to release amylases to act on starch and proteases to digest protein?

A) Malting
B) Preparing a mash
C) Aging
D) Fermentation
E) Wort boiled with hops

Question 26

Yeast fermentation in breads is aerobic.

Question 27

The yeast used in making bread, beer, and wine is ______.

A) Spirulina
B) Leuconostoc mesenteroides
C) Propionibacterium
D) Saccharomyces cerevisiae
E) Streptococcus lactis

Question 28

Analysis of a water sample by a series of presumptive, con?rmatory, and completed tests that provide an estimate of coliform numbers in the water is called the ______.

A) most probable number (MPN)
B) standard plate count
C) membrane ?lter method
D) coliform count

Question 29

Which of the following is not a desired outcome from using microbes in making bread?

A) Giving ?avor and odor
B) Conditioning the dough to make it workable
C) Leavening
D) Producing ethyl alcohol
E) Helping the dough rise

Question 30

Which step in making beer involves inoculating the wort with a species of Saccharomyces?

A) Preparing a mash
B) Fermentation
C) Malting
D) Wort boiled with hops
E) Aging

Question 31

Which organism is used to initiate the fermentation of cabbage to make sauerkraut?

A) Propionibacterium
B) Streptococcus lactis
C) Leuconostoc mesenteroides
D) Spirulina
E) Saccharomyces cerevisiae

Question 32

Which step in making beer involves soaking malt grain, grinding it, and heating with sugar and starch?

A) Malting
B) Aging
C) Wort boiled with hops
D) Preparing a mash
E) Fermentation

Question 33

Media used for coliform enumeration include chemicals that change color depending on the enzymes present in the microbes, thereby allowing a count of total bacteria and total coliforms from a single plate. This type of medium is termed ______.

A) selective
B) de?ned
C) complex
D) differential

Question 34

A 100 ml sample of water is ?ltered through a sterile membrane, and the membrane is transferred to a plate of m-Endo agar. Following overnight incubation at 37°C, 57 green metallic colonies appear. The coliform count is _______.

A) 0.57 per 100 ml
B) 57 per 100 ml
C) 5700 per 100 ml
D) too numerous to count

Question 35

You want to make wine that will be 20-25% alcohol, but wine rarely gets to that concentration of alcohol. What can you do to accomplish your goal of high-yield alcohol production?

A) Add more sugar to your starting material
B) Add brandy to your wine
C) Let your fermentation go longer
D) Find an alcohol-tolerant yeast strain

Question 36

Which step in wine production involves crushing fruit?

A) Aging
B) Storage
C) Fermentation
D) Malting
E) Preparation of must

Question 37

Which of the following is not a gas-forming microbe used to make bread?

A) Saccharomyces cerevisiae
B) Streptococcus lactis
C) Coliform bacteria
D) Heterofermentative lactic acid bacteria
E) Clostridium perfringens

Question 38

Which of the following statements is true?

A) Microorganisms can be a food source.
B) Microbial metabolism can alter a food to improve its ?avor.
C) Not all microorganisms in food cause foodborne disease.
D) All of the choices are correct.

Question 39

The products of maltose fermentation in bread-making are ______.

A) ethanol and water
B) ethanol and carbon dioxide
C) lactic acid and carbon dioxide
D) lactic acid and water
E) carbon dioxide and water

Question 40

Which organisms are used to make salt pickles?

A) Propionibacterium and Spirulina
B) Saccharomyces cerevisiae and Leuconostoc mesenteroides
C) Leuconostoc mesenteroides and Spirulina
D) Pediococcus cerevisiae and Lactobacillus plantarum
E) Streptococcus lactis and Lactobacillus

Question 41

What is made by fermenting milk with Streptococcus thermophilus and Lactobacillus bulgaricus?

A) Yogurt
B) Cheese
C) Sour cream
D) Tofu
E) Ke?r

Question 42

Most cases of food poisoning occur in the home, not restaurants.

Question 43

Which organism is not a common cause of food poisoning, but its frequency is dramatically increasing as warmer ocean temperatures expand its habitat toward the U.S.?

A) Campylobacter
B) Salmonella
C) Shiga-toxin-producing
D) Vibrio
E) coli

Question 44

The organism used to make bleu cheese is ______.

A) Penicillium roqueforti
B) Propionibacterium
C) Micrococcus
D) Leuconostoc mesenteroides
E) Streptococcus lactis

Question 45

All of the following are food-borne pathogens except ______.

A) Lactobacillus acidophilus
B) Salmonella
C) Clostridium perfringens
D) Staphylococcus aureus
E) Campylobacter jejuni

Question 46

Preservation of food to limit microbial survival and growth includes _______.

A) high temperature and pressure
B) pasteurization
C) refrigeration and freezing
D) irradiation
E) All of the choices are correct.

Question 47

Rennin is added to cheese to help preserve it.

Question 48

A good range of temperature to store food is ______.

A) 0° to 50°C
B) 20° to 80°C
C) below 10°C and above 80°C
D) below 4°C and above 60°C
E) below -10°C and above 100°C

Question 49

Which statement is true regarding pasteurization?

A) It does not kill all microorganisms in milk.
B) The process was ?rst used in the wine industry.
C) During pasteurization, the heating is done very quickly to prevent a change in the integrity and taste of the product.
D) All statements are true.

Question 50

"Live and Active Cultures" on the label of many yogurt products means that _______.

A) the product may become contaminated by microbes if exposed to air
B) the product contains live bacteria
C) yeast cultures were used to produce the yogurt
D) the product was made by fermentation but then pasteurized

Question 51

Which of the following is/are microorganism/s that can be used as food?

A) Spirulina
B) Methylophilus methylotrophus
C) Algae
D) Fusarium graminearum
E) All of the choices are correct.

Question 52

Preventing the incorporation of microbes into food can by achieved by _______.

A) washing fruits and vegetables
B) aseptic techniques for handling meat, eggs, and milk
C) handwashing and proper hygiene in the kitchen
D) avoiding cross-contamination of utensils and cutting boards
E) All of the choices are correct.

Question 53

A quick warming of chicken or eggs is enough to kill Salmonella.

Question 54

Which bacteria ferment lactose in milk, producing acids that curdle the milk?

A) Leuconostoc mesenteroides
B) Streptococcus lactis and Lactobacillus
C) Pediococcus
D) Saccharomyces cerevisiae
E) Spirulina

Question 55

The starting substrate for vinegar production is ______.

A) water
B) an alcoholic solution
C) a salt solution
D) fruit juice

Question 56

The ?rst stage in making vinegar involves fermentation by ______.

A) Acetobacter
B) Saccharomyces
C) Gluconobacter
D) Pediococcus
E) Spirulina

Question 57

Identify the chemical formula missing from the following equation. Yeast + _______ ? 2C2H5OH + 2CO?

A) O?
B) C?H??O?
C) C5H??O5
D) H?O
E) CH?CHO

Question 58

Freezing chicken does not kill Salmonella.

Question 59

You ask the butcher to grind a sirloin roast to be used for hamburger. You family likes hamburgers rare, so you undercook the meat. Unfortunately, within two days they develop the symptoms of gastrointestinal disease: diarrhea, bloating, and vomiting. Which of the following statements best
Describes what happened?

A) The meat grinder was contaminated, and bacteria were transferred and distributed throughout the meat.
B) The meat became contaminated by bacteria from other foods in your refrigerator.
C) The meat became contaminated by bacteria on the barbeque grill, coating both sides of the hamburger patties.
D) The animal was sick before slaughter, and the sirloin was contaminated.

Question 60

Which of the following would be found within the Hazard Analysis and Critical Control Point guidelines for food safety?

A) Parameters for oyster harvests based on water quality assessment
B) Temperature requirements for pasteurization of milk
C) Precise de?nitions to distinguish fruit juice from fruit nectar
D) All of these are found in the HACCP management program.

Question 61

A device in which mass cultures are grown, reactions take place, and product develops is a/an ______.

A) activator
B) incubator
C) sparger
D) fermentor

Question 62

Which of the following is an example of a secondary metabolite?

A) Toxin produced by species of Clostridium
B) Alcohol produced by Saccharomyces during fermentation
C) Lactic acid made during yogurt production.
D) All of these are secondary metabolites.

Question 63

Which of the following activities uses microbial biotransformation?

A) Sewage treatment
B) Yogurt production
C) Alcohol production
D) Production of antibiotics

Question 64

Nitrates and nitrites are used in cured meats to prevent ______.

A) S. aureus food poisoning
B) botulism intoxication
C) infection from fruits and nuts
D) mold growth

Question 65

Which of the following is not a step in the mass production of an organic substrate in a fermentor?

A) Add enzymes to catalyze all required steps in the process.
B) Harvest cells and purify the product.
C) Adjust the environmental conditions for optimal growth of the organism.
D) Remove waste products and dispose responsibly.
E) Inoculate the sterile media in the growth vessel with the microbe of interest.

Question 66

A common substrate for industrial fermentation products is ______.

A) cholesterol
B) alcohol
C) molasses
D) nucleotides

Question 67

In batch fermentation, substrate is added continuously, and the product is siphoned off throughout the run.

Question 68

What type of radiation is best for destroying microbes throughout food?

A) Infrared
B) Visible light
C) Gamma rays
D) Ultraviolet
E) Microwaves

Question 69

Irradiated food becomes radioactive.

Question 70

In industrial microbiology, microbes growing on inexpensive nutrients are induced to synthesize valuable products such as amino acids, nucleotides, organic acids and vitamins.

Question 71

Dehydration is an excellent microbicidal method.

Question 72

Which is not used as a chemical preservative in food?

A) Antibiotics
B) Organic acids
C) Sul?te
D) Ethylene oxide gas
E) Salt

Question 73

The disadvantage of batch fermentations, as opposed to continuous feed systems, is that _______.

A) the end product is not as pure as the product made by the continuous feed process
B) new substrate must be added to the fermentor continuously for the fermentation to continue
C) it is small scale production of a product
D) there is a limit to the amount of product formed since all materials are added to the fermentor at the beginning

Question 74

Bacteriophages sprayed on cold cuts are effective against ______.

A) Listeria
B) Clostridium
C) S. aureus
D) Mycobacterium
E) coliforms

Question 75

You have to determine what method is best to prevent the growth of microorganisms in your company's food, ham roasts. This method should be e?cient, have a high kill rate, not change the food integrity or taste for the most part, and not add much in the way of chemicals. What would you
Choose?

A) Pasteurization
B) Food preservatives
C) Filtration
D) Freezing
E) Gamma radiation

Question 76

Which enzyme is used in medicine as a blood thinner?

A) Protease
B) Streptokinase
C) Rennet
D) Cellulase
E) Hemolysin

Question 77

You have never seen a jar of jelly contaminated with microbial growth, even though it is used for months at a time. Which is the best explanation?

A) A variety of chemicals are added to jelly to make it inhospitable for bacteria.
B) Jelly is pasteurized.
C) Jelly is ?lter sterilized.
D) Jelly has a high osmotic pressure.

Question 78

Industrial microbiology is used in the production of ______.

A) antibiotics
B) hormones
C) vitamins
D) vaccines
E) All of the choices are correct.

Question 79

Secondary metabolites are essential molecules needed by the microorganism.

Question 80

Which of the following is not true of industrial microbiology?

A) Secondary metabolites include amino acids.
B) Select microbial strains are not controlled by feedback mechanisms.
C) Primary metabolites are essential to a microbe's function.
D) Growth environment is enhanced to increase metabolite synthesis.