Deck 16: The Microbiology of Food and Water

Question 1

Evidence of microbial food spoilage requires the presence of at least _________ microbes per gram.

A) 100
B) 1000
C) 10,000 d 100,000
E) 1,000,000

Answer 1

E

Question 2

When you add salt to meat for preservation you are

A) increasing the water activity of the meat.
B) decreasing the water activity of the meat.
C) increasing the pH of the meat.
D) decreasing the pH of the meat.
E) decreasing the nutrient content of the meat.

Answer 2

B

Question 3

The fungus Penicillium is used in the production of

A) blue cheese.
B) cheddar cheese.
C) limburger cheese.
D) American cheese.
E) Colby cheese.

Answer 3

A

Question 4

The most common disease associated with improperly canned food is

A) botulism.
B) tetanus.
C) gastroenteritis.
D) colitis.
E) stomach ulcer.

Question 5

Which one of the following foods is not a fermented milk product?

A) Swiss cheese
B) Kefir
C) Butter
D) Butter milk
E) Yogurt

Question 6

Which one of the following is an extrinsic factor that affects that rate of food spoilage?

A) The storage temperature
B) The pH of the food
C) The skin on a fruit
D) The water content of the food
E) The nutrient content of the food

Question 7

All of the following microbes play an important role in the production of fermented milk products except for

A) Lactobacillus.
B) Leuconostoc.
C) Lactococcus.
D) Saccharomyces.
E) Streptococcus.

Question 8

This microorganism is often used to make fermented semi-dry sausages and salami.

A) Leuconostoc
B) Pediococcus
C) Saccharomyces
D) Aspergillus
E) Lactobacillus

Question 9

LHT Pasteurization is a method of preservation that involves heating the liquid to _______ °C for 30 min.

A) 45
B) 63
C) 85
D) 100
E) 121

Question 10

What bacterium is used in the production of Swiss cheese to give it its characteristic flavor and also the holes from carbon dioxide production?

A) Pediococcus
B) Leuconostoc
C) Propionibacterium
D) Clostridium
E) Pseudomonas

Question 11

Which one of the following foods would have the highest water activity?

A) Almonds
B) Honey
C) Dried Beans
D) Apple
E) Rice

Question 12

Pickling is a preservation method that uses __________ to help preserve the food.

A) alcohol
B) heat
C) acid
D) freezing
E) spices

Question 13

Which of the following type of radiation may be used to sterilize food?

A) Long range ultra-violet
B) Visible light
C) Radio waves
D) Ionizing
E) Infrared

Question 14

Vacuum packaging inhibits the growth of microbes that

A) are obligate anaerobes.
B) rely on fermentation for energy metabolism.
C) are aerotolerant anaerobes.
D) rely on aerobic respiration for growth.
E) are chemolithotrophs.

Question 15

Most milk sold in stores today has an extended shelf life primarily because of

A) canning techniques.
B) refrigeration.
C) Tyndallization.
D) high temperature short term pasteurization.
E) the addition of chemical preservatives.

Question 16

The most common food preservation method used in US households is

A) canning.
B) curing meat.
C) refrigeration.
D) heating.
E) freeze-drying.

Question 17

Lyophilization is

A) the acidification of food for long term storage.
B) a type of canning technique.
C) sun-dried food.
D) freeze-drying of food.
E) salting of food for storage.

Question 18

The protease rennin is used in the production of

A) butter.
B) yogurt.
C) kefir.
D) cheese.
E) ice cream.

Question 19

Small protein molecules produced by a microorganism that adversely affect a closely related microorganism are called

A) siderophores.
B) bacteriocins.
C) lysozymes.
D) beta-blockers.
E) proteases.

Question 20

Canning is a technique used in food preservation.The food to be canned is heated to boiling for an hour

A) in the presence of high salt.
B) under acidic conditions.
C) with a preservative added for long term storage.
D) under pressure of 10 - 15 psi.
E) and immediately chilled after boiling.

Question 21

The pH of an orange is an intrinsic factor that affects the shelf-life of the fruit.

Question 22

Foods with high water activity will usually spoil faster than foods with a low water activity.

Question 23

Anaerobic digesters at wastewater treatment plants are used to

A) reduce nitrogen and phosphorus in wastewater.
B) remove toxic organic pollutants.
C) remove potential pathogens.
D) treat wastewater effluent.
E) treat sludge and particulates collected during waste treatment.

Question 24

Vinegar production occurs through the oxidation of ethanol by

A) lactic acid bacteria.
B) the yeast Saccharomyces.
C) various molds.
D) sulfate-reducing bacteria.
E) acetic acid bacteria.

Question 25

Staphylococcus aureus causes foodborne illness through

A) the production of an enterotoxin that contaminates prepared foods.
B) a break in the skin during food preparation.
C) the ingestion of the microbe which grows in the large intestine to produce symptoms.
D) the production of an exotoxin after ingestion of the microbe.
E) the consumption of undercooked meat.

Question 26

Canning is the most prominent method of food preservation in industrialized countries today.

Question 27

All of the following are goals of wastewater treatment except

A) reduction of total organic content (TOC).
B) removal of harmful pathogens.
C) enhancement of the taste of water.
D) removal of nitrogen.
E) removal of phosphorus.

Question 28

Fermented soybean products,like miso and tempeh,are produced using

A) lactic acid bacteria.
B) molds.
C) propionate bacteria.
D) acetic acid bacteria.
E) Saccharomyces.

Question 29

The main goal of the primary treatment phase of wastewater treatment is the

A) reduction of total organic content (TOC).
B) removal of pathogenic microbes.
C) reduction of nitrogen.
D) removal of particulate matter.
E) removal of toxic chemicals.

Question 30

Which of the following methods use microbial biofilms for secondary phase of wastewater treatment?

A) trickling filter
B) activated sludge
C) anaerobic digester
D) nitrification tank
E) oxidation pond

Question 31

The ________________ is a measure of the amount of oxygen required for the microbial oxidation of organic compounds in a water source.

A) chemical oxygen demand
B) biological oxygen demand
C) respiration rate
D) carbon dioxide production
E) cell yield

Question 32

Pasteurization is a process of food preservation that results in sterilization.

Question 33

All of the following are processes that may be used in the treatment of drinking water except

A) filtration.
B) activated sludge digestion.
C) flocculation.
D) chlorination.
E) sedimentation.

Question 34

The addition of salt to certain food for preservation has been used for hundreds of years.Salt helps to preserve food by lowering the water activity.

Question 35

The gas __________ is frequently recovered from anaerobic digesters at a waste treatment plant.

A) methane
B) carbon dioxide
C) hydrogen
D) nitrogen
E) argon

Question 36

The release of high levels of nitrogen and phosphorus into streams after wastewater treatment will result in

A) the production of high quality water for plant irrigation.
B) water that tastes bad.
C) eutrophication of the stream.
D) increased nutrients for the fish in the stream.
E) increase in oxygen levels in the stream.

Question 37

The activated sludge method of wastewater treatment uses

A) a microbial biofilm for organic carbon reduction.
B) an inoculum from the previous activated sludge treatment.
C) chemolithotrophic bacteria for carbon reduction.
D) special chemicals for the removal of organic pollutants.
E) large screens to filter out particulate matter.

Question 38

An example of an organism that causes a foodborne infection is

A) Staphylococcus aureus.
B) Campylobacter jejuni.
C) Clostridium perfringens.
D) Clostridium botulinum.
E) Bacillus cereus.

Question 39

Which microbe listed below causes foodborne intoxication?

A) Shigella
B) Salmonella
C) Staphylococcus
D) Campylobacter
E) Vibrio

Question 40

Ozonation is a wastewater treatment used to

A) remove organic pollutants.
B) disinfect wastewater.
C) reduce nitrogen levels in the water.
D) remove heavy metals that may be present in wastewater.
E) remove phosphorus from wastewater.

Question 41

A person eats some leftover potato salad from a picnic and becomes ill within three hours.This type of food poisoning is referred to as a "food-infection".

Question 42

Describe the activated sludge method for treatment of wastewater effluent.What is the major goal of this method?

Question 43

Many bacteria that are used for the production of various fermented milk products belong to the lactic acid bacteria group.

Question 44

Describe the process of vinegar production by the trickle method.Name the two genera of bacteria involved.Why do they produce vinegar?

Question 45

Compare and contrast a food-borne infection to intoxication.

Question 46

Vinegar is made by bacteria from one of two genera,either Gluconobacter or ________________.

Question 47

The bacterium that gives Swiss cheese its characteristic flavor and holes is in the genus ____________.

Question 48

Chemical food preservatives like sodium benzoate,acetic acid,and propionate are all weak acids.

Question 49

Small proteins produced by some bacterial to inhibit the growth of closely related bacteria are called __________________.

Question 50

One of the main reasons for wastewater treatment is to reduce the BOD.

Question 51

Food storage temperature is an ____________ factor that affects the rate at which a food will spoil.

Question 52

The amount of water in a food that is available to microorganisms is referred to as ________ ______.

Question 53

Irradiation of food by gamma radiation will make the food radioactive.