Biology

Microorganisms in Food Production

1,120 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

Many microorganisms like Aspergillus niger, Penicillium luteum, Candida catenula, Candida guilliermondii and Corynebacterium species produce citric acid. Which of the following organisms is genetically modified for improved industrial production of citric acid?

  1. Candida catenula

  2. Penicillium luteum

  3. Aspergillus niger

  4. Corynebacterium species
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For improved industrial production of citric acid, mutant strains of Aspergillus niger have been developed. These mutant strains can tolerate high sugar concentration and low pH with reduced synthesis of undesirable byproducts.

Multiple choice

The most preferred strain for beta-carotene production is

  1. Phycomyces blakesleeanus

  2. Blakeslea trispora

  3. Choanephora cucurbitarum

  4. Clostridium aceto­butylicum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Blakeslea trispora is the most preferred strain for production of beta-carotene due to its high yield. It produces 3 g/l beta-carotene.

Multiple choice

Which of the following does not regulate L-lysine microbial synthesis?

  1. Aspartate kinase

  2. Dihydrodipicolinate synthase

  3. Phosphoenol pyruvate carboxylase

  4. Succinylase
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Phosphoenol pyruvate carboxylase regulates the production of L-glutamate by converting phosphoenol pyruvate to oxaloacetate, which is required for glutamic acid synthesis.

Multiple choice

Which of the following conditions favour(s) high amount of glutamic acid synthesis by Corynebacterium glutamicum?

A. High activity of glutamate dehydrogenase B. Low activity of α-ketoglutarate dehydrogenase C. Resistance to penicillin D. Activity of PPP carboxylase and pyruvate carboxylase

  1. Option A

  2. Options A, B, C and D

  3. Options A, B and C

  4. Options A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

C. glutanicum, i.e. glutamic acid-producing bacteria have a high activity of glutamate dehydrogenase and a low activity of α-ketoglutarate dehydrogenase, which favours high amount of glutamic acid synthesis by Corynebacterium glutanicum.

Multiple choice

Antigenic shift is seen only with influenza A viruses. It results usually from the replacement of the hemagglutinin and generally involves

  1. single point mutation

  2. random point mutations

  3. interchanging of large segments of the viral genome with other viruses

  4. rearrangement of the viral structural architecture

  5. regression to an earlier variant
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The ability to interchange large segments of the genome with a viral reservoir in other animal species is the basis of antigenic shift leading to radical change in antigen, particularly crucial antigens giving protective immunity such as the viral hemagglutinin.

Multiple choice

H5N1 virus is a subtype of

  1. influenza virus D

  2. influenza virus B

  3. influenza virus A

  4. influenza virus C

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

H5N1 is a subtype of Influenza A virus. Influenza A viruses are classified based on two surface proteins: hemagglutinin (H) and neuraminidase (N). H5N1 is an avian influenza subtype that can infect humans and has caused pandemic concerns.

Multiple choice

In a culture, it is desirable to have all the microorganisms in a physiological steady state. Which of the following cultures should be used to get the desired outcome?

  1. Batch culture

  2. Synchronous culture

  3. Continuous culture

  4. Pure culture
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Microorganisms can be grown in a physiological steady state under constant environmental conditions in a continuous culture. In the steady state, growth occurs at a constant specific growth rate and all culture parameters remain constant.

Multiple choice

________ and ________ are examples of enriched media.

  1. Blood agar, Hektoen Enteric Agar

  2. Eosin Methylene Blue agar, Mannitol salt agar

  3. Hektoen Enteric Agar, Mannitol salt agar

  4. Eosin Methylene Blue agar, MacConkey agar

  5. Blood agar, Chocolate agar
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Blood agar is both a differential and an enriched medium. The blood that is incorporated into this medium is an enrichment ingredient for the cultivation of fastidious organisms such as the Streptococcus species. Chocolate agar is an enriched culture media commonly used for primary isolation of Haemophilus species from clinical specimens.