MCB Module 3.4

Vinegar production occurs through the oxidation of ethanol by:

lactic acid bacteria.

sulfate-reducing bacteria.

various molds.

acetic acid bacteria.

acetic acid bacteria.

Vacuum packaging inhibits the growth of microbes that:

rely on aerobic respiration for growth.

are aerotolerant anaerobes.

rely on fermentation for energy metabolism.

are obligate anaerobes.

rely on aerobic respiration for growth.

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

nitrogen

carbon dioxide

argon

methane

Methane

Why is pasteurization an important step in milk fermentation for yogurt or cheese?

to prevent growth of undesired bacteria

to increase the biological oxygen demand

to improve taste and consistency of the product

to reduce the water activity of milk

to prevent growth of undesired bacteria

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

Almonds

Rice

Dried Beans

Apple

Apple

Ozonation is a wastewater treatment used to:

disinfect wastewater.

reduce nitrogen levels in the water.

remove phosphorus from wastewater.

remove organic pollutants.

disinfect wastewater.

The most common food preservation method used in US households is:

canning.

curing meat.

refrigeration.

freeze-drying.

refrigeration.

Which one of these bacterial groups are essential for cheese production:

methanogens

lactic acid bacteria

methylotrophs

Staphylococcus aureus

lactic acid bacteria

Which one of these is NOT a primary goal of wastewater treatment:

reduction in levels of inorganic nutrients

reduction in organic carbon levels

eutrophication of the effluent

removal or inactivation of harmful microbes

eutrophication of the effluent

The top five annual food-borne diseases in the US include:

Escherichia coli

lactic acid bacteria

Salmonella

methanogens

salmonella

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

concentration of methane production

chemical oxygen demand

biological oxygen demand

cell yield

biological oxygen demand