Question 1

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

Accepted Answer

Malting involves sprouting and softening the barley to release amylases to act on starch, and proteases to digest protein.

Question 2

Which is not used as a chemical preservative in food?

Accepted Answer

Iodine is not commonly used as a chemical preservative in food. It is sometimes used as a disinfectant or sanitizer, but not as a preservative. The other options listed (organic acids, sulfite, ethylene oxide, and salt) are all commonly used as food preservatives.

Question 3

These bacteria ferment milk lactose, producing acids that curdle the milk:

Accepted Answer

Streptococcus lactis and Lactobacillus are both known for their ability to ferment lactose in milk, producing lactic acid and causing the milk to curdle. This process is commonly used to produce dairy products such as yogurt and cheese.

Question 4

Which of the following causes food intoxication?

Accepted Answer

Staphylococcal enteritis is caused by the ingestion of food contaminated with the bacterium Staphylococcus aureus, which produces a heat-stable toxin that is not destroyed by cooking. Symptoms typically include rapid onset of nausea, vomiting, and abdominal cramps, with recovery usually occurring within one to two days.

Question 5

During which phase of growth would a primary metabolite be produced?

Accepted Answer

Primary metabolites are produced during the exponential phase of growth, which is characterized by rapid cell division and increase in biomass. During this phase, the cells prioritize the production of essential organic molecules such as amino acids, nucleotides, and organic acids necessary for their survival and growth.

Question 6

Which of the following enzymes are produced by microorganisms on an industrial scale?

Accepted Answer

All of the enzymes listed (pectinase, cellulase, amylase, and keratinase) are produced by microorganisms on an industrial scale.

Question 7

To prevent the overgrowth of cyanobacteria and algae in water reservoirs, the water is often treated with

Accepted Answer

Copper sulfate is commonly used as an algaecide to prevent the overgrowth of cyanobacteria and algae in water reservoirs. It works by disrupting the cellular processes of the algae and cyanobacteria, preventing their growth and proliferation. Copper sulfate is effective, widely available, and relatively lowcost, making it a practical choice for water treatment. However, it is important to use copper sulfate only in the recommended concentrations, as excessive doses can be harmful to aquatic life and the environment.

Question 8

Preservation of food to limit microbial survival and growth includes

Accepted Answer

All of the choices listed (high temperature, pasteurization, refrigeration and freezing, and irradiation) can be effective methods for preserving food and limiting microbial survival and growth. Each method has its own advantages and limitations depending on the type of food being preserved, desired shelf life, and other factors. Therefore, using a combination of these methods is often the most effective approach to ensuring the safety and quality of preserved foods.

Question 9

In 2006, the Food and Drug Administration approved the spraying of bacteriophages onto ready-to-eat meat products to

Accepted Answer

The answer of In 2006, the Food and Drug Administration...

Question 10

All of the following are foodborne pathogens except

Accepted Answer

Salmonella, Campylobacter, Clostridium, and Staphylococcus aureus are all known foodborne pathogens, whereas Streptococcus is not typically associated with foodborne illness.

Question 11

All of the following foods are preserved using high osmotic pressure except

Accepted Answer

Bread is not preserved using high osmotic pressure. Instead, it is preserved using low osmotic pressure through techniques such as baking or freezing.

Question 12

Which is incorrect about food-borne illnesses?

Accepted Answer

Reports of food poisoning are actually increasing in the United States, as more people are becoming aware of the symptoms and reporting their illnesses.

Question 13

This organism is used to initiate the fermentation of cabbage to make sauerkraut:

Accepted Answer

Leuconostoc mesenteroides is commonly used as a starter culture for sauerkraut fermentation. It is a lactic acid bacteria that produces the characteristic tangy flavor of sauerkraut.

Question 14

Which of the following are mismatched?

Accepted Answer

Propylene oxide gas is not used in dairy. It is primarily used for sterilization of certain food equipment and packaging materials.

Question 15

Fermenters have a built-in device called a sparger.What does a sparger do?

Accepted Answer

A sparger is used to aerate the medium in a fermenter, providing a continuous supply of oxygen, promoting aerobic growth of microbes, and enhancing the efficiency of the fermentation process.

Question 16

This organism is used to make Swiss cheese:

Accepted Answer

The answer of This organism is used to make Swiss...

Question 17

What is made by adding Streptococcus thermophilus and Lactobacillus bulgaricus to milk?

Accepted Answer

Adding Streptococcus thermophilus and Lactobacillus bulgaricus to milk results in the fermentation of lactose into lactic acid, creating the thick and creamy texture of yogurt.

Question 18

Bacillus thuringiensis produce

Accepted Answer

Bacillus thuringiensis is known for producing a toxin that acts as a biopesticide. It is commonly used in agriculture to control insect pests, specifically those that damage crops. It is not known to cause food poisoning, and it is not used in cheese-making or as a food source for humans. Therefore, the best choice is option B.

Question 19

Water moves through sand beds and activated charcoal in this step of water purification:

Accepted Answer

Filtration is the process where water is forced through a filter, which removes impurities such as sand and activated charcoal. Chlorination adds a disinfectant to kill any remaining bacteria or viruses, aeration and settling allows suspended particles to settle to the bottom, sedimentation involves the settling of heavier particles, and storage involves holding the treated water in a reservoir before distribution.

Question 20

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

Accepted Answer

Saccharomyces cerevisiae is the yeast commonly used in making bread, beer, and wine due to its ability to ferment sugar and produce carbon dioxide, which causes dough to rise and alcoholic beverages to be produced.

Quiz 27: Applied and Industrial Microbiology