Biology

Microorganisms in Food Production

1,086 Questions

Microorganisms play a vital role in food production through processes like fermentation and bioprocessing. Questions on this topic cover the use of yeast, bacteria, and industrial microbiology. These concepts are important for science sections in various competitive exams.

Alcoholic fermentationDairy beverage productionIndustrial ethanol preparationCitric acid productionBiodigester temperature

Microorganisms in Food Production Questions

Multiple choice

Which of the following microorganisms is/are used in the making of chocolate? A. Kloeckera africana B. Kocuria rhizophila C. Gluconacetobacter oboediens D. Kluyveromyces marxianus

  1. A only

  2. B only

  3. B and C

  4. A and C

  5. A and D
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The fungi, Kloeckera africana and Kluyveromyces marxianus both are used in the making of chocolate. The bacteria Kocuria rhizophila is used in the making of cheese and the bacteria Gluconacetobacter oboediens is used in the making of vinegar.

Multiple choice

Match Group I (fermented food products) with Group II (corresponding microorganisms).

Group-I Group-II
P. Cheese 1. Leuconostoc mesenteroides and Lactobacillus plantarum
Q. Sauerkraut 2. Lactobacillus acidophilus and Lactobacillus delbrueckii
R. Kefir 3. Lactobacillus delbrueckii and Streptococcus thermophillus
S. Yoghurt 4. Lactobacillus casei and Streptococcus thermophillus

  1. P - 1, Q - 3, R - 4, S - 2

  2. P - 4, Q - 1, R - 3, S - 2

  3. P - 1, Q - 2, R - 3, S - 4

  4. P - 2, Q - 4, R - 1, S - 3

  5. P - 2, Q - 3, R - 4, S - 1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The microorganisms in the making of cheese are Leuconostoc mesenteroides and Lactobacillus plantarum, for sauerkraut the microorganisms are Lactobacillus delbrueckii and Streptococcus thermophillus, for Kefir making Lactobacillus casei and Streptococcus thermophillus and the microorganisms in the making of yoghurt are Lactobacillus acidophilus and Lactobacillus delbrueckii. Hence, the correct answer using the codes is P-1, Q-3, R-4, S-2.

Multiple choice

Which of the following matchings is incorrect?

  1. Chocolate agar: Gram-negative enteric bacteria

  2. MacConkey agar: Gram-negative bacteria

  3. Sabouraud agar: Yeast, mould and bacteria that grow in acidic conditions

  4. Potato dextrose agar: Yeast and mould from food

  5. Endo agar: Coliform bacteria
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Chocolate agar is used to grow fastidious gram-positive cocci.

Multiple choice

Which of the following microbes is used to produce yoghurt?

Fermentation defines incomplete oxidation produced by microorganisms acting on compounds for which the most part are carbohydrate or carbohydrate-like in nature. A variety of products are produced many of which have great industrial importance. In dairy industry fermented milks are produced by inoculating pasteurized milk with known culture of microorganisms known as starter culture.

  1. Saccharomyces cerevisiae

  2. Lactobacillus bulgaris

  3. Chondrus sp

  4. Streptococcus lactis

  5. Streptococcus thermophilus

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Streptococcus thermophilus is used to produce yoghurt which is semi-solid, jelly-like, and non-alcoholic made from milk where milk is partly evaporated  and  fermented by microbe starter. Organism produces 1.5-2.5% lactic acid.

Multiple choice

Which of the following microbes is used to produce cheese?

Fermentation defines incomplete oxidation produced by microorganisms acting on compounds for which the most part are carbohydrate or carbohydrate-like in nature. A variety of products are produced many of which have great industrial importance. In dairy industry fermented milks are produced by inoculating pasteurized milk with known culture of microorganisms known as starter culture.

  1. Chondrus sp

  2. Streptococcus lactis

  3. Streptococcus thermophilus

  4. Lactobacillus bulgaris

  5. Saccharomyces cerevisiae
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Lactobacillus bulgaris is used to produce cheese. The pasteurized milk inoculation with Lactobacilli is followed by curdling, draining of curd  and  pressing in desired shapes, slat addition, ripening.

Multiple choice

Which of the following acids is the precursor for pencilllin G biosynthesis during fermentation process?

  1. Phenylacetic acid

  2. Phenoxyacetic acid

  3. Acetic acid

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During Penicillin G fermentation, Penicillium chrysogenum incorporates phenylacetic acid (or its precursor phenylacetamide) into the penicillin nucleus, forming the characteristic benzyl side chain of Penicillin G. This precursor addition is essential for biosynthesis. Phenoxyacetic acid is used for Penicillin V, and acetic acid is not a penicillin precursor.

Multiple choice

Match the fermented food products in Group I with the microorganisms in Group II

 
Group I Group II
A. Yoghurt 1. Lactobacillus acidophilus and Lactobacillus delbrueckii
B. Cheese 2. Leuconostoc mesenteroides and Lactobacillus plantarum
C. Sauerkraut 3. Lactobacillus delbrueckii and Streptococcus thermophillus
D. Kefir 4. Lactobacillus casei and Streptococcus thermophillus

  1. A - 1, B - 4, C - 2, D - 3

  2. A - 4, B - 3, C - 1, D - 2

  3. A - 3, B - 4, C - 2, D - 1

  4. A - 3, B - 2, C - 4, D - 1
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Yoghurt is fermented by L. delbrueckii and S. thermophillus (3), cheese involves L. casei and S. thermophillus (4), sauerkraut uses L. mesenteroides and L. plantarum (2), while kefir traditionally contains L. acidophilus and L. delbrueckii (1).

Multiple choice

The given two columns indicate some of the fermentation products and the microbial cultures used for the production. Identify the correct set of groups from the four given options.

 
Fermentation products Microbial cultures
1. Ethanol (a) Aspergillus niger
2. Streptomycin (b) Zymomonas mobilis
3. Citric acid (c) Streptomyces griseus
4. Cellulase (d) Trichoderma reesei

  1. 1 - a, 2 - b, 3 - c, 4 - d

  2. 1 - b, 2 - c, 3 - a, 4 - d

  3. 1 - b, 2 - c, 3 - d, 4 - a

  4. 1 - d, 2 - c, 3 - b, 4 - a
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ethanol is produced by Zymomonas mobilis (b), streptomycin is an antibiotic from Streptomyces griseus (c), citric acid is fermented by Aspergillus niger (a), and cellulase is produced by Trichoderma reesei (d).

Multiple choice

Organisms like yeast can survive in the absence of oxygen and they produce alcohol by utilising glucose. What are such organisms called?

  1. Anaerobes

  2. Cellulites

  3. Respirants

  4. Aerobes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

There are some organisms such as yeast that can survive in the absence of air. They are called anaerobes. They get energy through anaerobic respiration. In the absence of oxygen, glucose breaks down into alcohol and carbon dioxide.