Food Microbiology Quiz

Which microorganism produces light brownish tinge in milk?

• Streptococcus lactis

• Pseudomonas syncyanea

• Lactobacillus casei

• Leuconostoc mesenteroides

Microorganisms and/or their metabolic products whose presence in given foods at certain levels may be used to assess existing quality or, better, to predict product shelf life. These are called:

• Hygiene indicators

• Safety indicators

• Shelf-life indicators

• Product indicators

These are Gram-negative asporogeneous rods that ferment lactose within 48 h & produce dark colonies with a metallic sheen on Endo-type agar

• Lactobacillus

• Coliforms

• Enterococci

• Bifidobacteria

This type of foodborne illness requiring the ingestion of high numbers of pathogenic microorganisms with short incubation period but without fever as one of the symptoms.

• Food intoxications

• Food infections

• Food toxico-infection

• Food poisoning

Which of these pathogenic microorganisms can cause food infection?

• Listeria monocytogenes

• Clostridium botulinum

• Staphylococcus aureus

• Bacillus cereus

What is the optimum temperature for growth of mesophilic microorganisms?

• 20-25 deg C

• 30-37 deg C

• 15-25 deg C

• 22-30 deg C

These are bacteria with optimum growth temperature at 20-30 deg C but also grow at low temperature.

• Psychrophilic

• Mesophilic

• Thermophilic

• Psychrotophic

For growth of yeast, what is the optimum pH value?

• pH 6.0-7.0

• pH 4.0-6.0

• pH 3.0-4.0

• pH 7.0-8.0

Which of the following components of plate count agar is the source for vitamins and amino acid?

• Agar

• Tryptone

• Yeast extract

• Glucose