Food Microbiology Quiz

What should be the percent reduction in the amount of agar to make a culture medium semi-solid?

• 0.4-0.8%

• 0.1-0.3%

• 0.2-0.5%

• 0.7-1.0%

Which of the following is an example of selective inhibitor used in common isolation and enumeration media with inhibitory properties against Gram positive bacteria?

• Brilliant green

• Lithium chloride

• Sodium azide

• Kanamycin

The use of coliforms as hygiene indicator originates from which of the following?

• Fruit & vegetable products

• Meat products

• Dairy products

• Fermented food products

The spoilage of sugars or concentrated solutions of sugars can be likely caused by which of the following:

• xerotolerant microorganisms

• proteolytic microorganisms

• aerotolerant microorganisms

• halophilic microorganisms

It is a gummy polysaccharide, a neutral glucan made by Leuconostoc mesenteroides from a molasses or refined-sucrose medium. It serves as a stabilizer for sugar syrups, ice cream and confections.

• Xanthan

• Dextran

• Chitosan

• Pullulan

The sampling plan which is used more in case of presence/absence tests such as in Salmonella

• Three-class sampling plan

• Two-class sampling plan

• Lot plan

• None of the given choices

Which of the following has a thicker peptidoglycan layer?

• Salmonella

• Pseudomonas

• Escherichia

• Streptococci

It can be used to determine the general microbiological quality of food

• Mesophilic aerobic count

• Psychrotrophic aerobic count

• Thermophilic count

• Colform count

In lauryl sulphate tryptose broth, which is the component that inhibits gram positive microorganisms?

• Tryptose

• Lactose

• Sodium lauryl sulphate

• Potassium dihydrogen phosphate

Which of the following can cause food intoxication?

• Listeria monocytogenes

• Yersinia enterecolitica

• Molds

• Aeromonas