Deck 25: Applied Microbiology and Food and Water Safety

Question 1

Potable water must be ______.

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

Answer 1

A

Question 2

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

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

Answer 2

B

Question 3

Which of the following statements regarding coliform bacteria is correct?

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

Answer 3

D

Question 4

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

Question 5

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

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

Question 6

Indicator bacteria for contaminated water are ______.

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

Question 7

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

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

Question 8

The first step in sewage treatment is ______.

A)chlorination
B)aeration and settling
C)filtration
D)sedimentation

Question 9

Which of the following statements regarding waterborne pathogens is incorrect?

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

Question 10

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

A)aeration
B)filtration
C)skimming
D)sludge digesting
E)chlorination

Question 11

Biotechnology includes all of the following except

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

Question 12

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

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

Question 13

Place the steps of the water purification process in order.
ق
B) Aeration, filtration and settling, chemical disinfection, release into a water reservoir
C) Chemical disinfection, aeration, filtration and settling, release into a water reservoir
D) Filtration and settling, chemical disinfection, aeration, release into a water reservoir

Question 14

The difference between water purification and sewage treatment is

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

Question 15

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

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

Question 16

Which of the following is not true of coliforms?

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

Question 17

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

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

Question 18

A 100 ml sample of water is filtered 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.

Question 19

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

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

Question 20

Primary sewage treatment includes ______.

A)skimming
B)sludge digesting
C)chlorination
D)filtration
E)aeration

Question 21

A 100 ml sample of water is filtered 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 22

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

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

Question 23

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)Let your fermentation go longer.
C)Add brandy to your wine.
D)Find an alcohol-tolerant yeast strain.

Question 24

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

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

Question 25

You made your first 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 find no alcohol--just really bad juice.What went wrong?

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

Question 26

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

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

Question 27

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

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

Question 28

Which organisms are used to make salt pickles?

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

Question 29

Yeast fermentation in breads is aerobic.

Question 30

A pure or mixed sample of known microbes added to food is a(n) ______.

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

Question 31

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

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

Question 32

Which step in wine production involves crushing fruit?

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

Question 33

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

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

Question 34

The source of wild yeasts carried in a biofilm on grapes is the ______.

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

Question 35

Which of the following statements is true?

A)Microorganisms can be a food source.
B)Microbial metabolism can alter a food to improve its flavor.
C)Not all microorganisms in food cause foodborne disease.
D) All statements are true.

Question 36

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

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

Question 37

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

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

Question 38

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)defined
B)selective
C)complex
D)differential

Question 39

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

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

Question 40

The basis of the membrane filter technique is that

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

Question 41

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 42

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 43

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 44

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

Question 45

The starting substrate for vinegar production is ______.

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

Question 46

Which statement is true regarding pasteurization?

A)It does not kill all microorganisms in milk.
B)The process was first 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 47

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

A)Tofu
B)Yogurt
C)Cheese
D)Kefir
E)Sour cream

Question 48

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 definitions to distinguish fruit juice from fruit nectar
D)All of these are found in the HACCP management program.

Question 49

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

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

Question 50

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

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

Question 51

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

Question 52

Identify the chemical formula missing from the following equation. Yeast + _________ → 2C₂H₅OH + 2CO₂

A)H₂O
B)C₅H₁₂O₅
C)O₂
D)C₆H₁₂O₆
E)CH₃CHO

Question 53

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 54

Rennin is added to cheese to help preserve it.

Question 55

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

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

Question 56

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

Question 57

The organism used to make bleu cheese is ______.

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

Question 58

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 2 days they develop the symptoms of gastrointestinal disease: diarrhea, bloating, and vomiting.Which of the following statements best describes what happened?

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

Question 59

Freezing chicken does not kill Salmonella.

Question 60

The first stage in making vinegar involves fermentation by ______.

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

Question 61

Industrial microbiology is used in the production of ______.

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

Question 62

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

Question 63

A device in which mass cultures are grown, reactions take place, and product develops is a(n) ______.

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

Question 64

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

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

Question 65

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

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

Question 66

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

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

Question 67

Secondary metabolites are essential molecules needed by the microorganism.

Question 68

Which of the following is not true of industrial microbiology?

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

Question 69

Which is not used as a chemical preservative in food?

A)Organic acids
B)Ethylene oxide gas
C)Sulfite
D)Antibiotics
E)Salt

Question 70

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 71

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

Question 72

Irradiated food becomes radioactive.

Question 73

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

Question 74

A common substrate for industrial fermentation products is ______.

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

Question 75

Which enzyme is used in medicine as a blood thinner?

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

Question 76

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

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

Question 77

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

Question 78

Which of the following activities uses microbial biotransformation?

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

Question 79

Dehydration is an excellent microbicidal method.

Question 80

Bacteriophages sprayed on cold cuts are effective against ______.

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