Question:
The following statements are describing the production of vitamins through from fermentation of whey. Choose the correct answer from the options given below:
(A) Vitamin B12 production by Propionibacterium shermanii can be done by using several substrates including cheese whey
(B) This organism (P. shermanii) grows aerobically and produces propionic acid, which accumulates in the medium.
(C) Most industrial processes for the production of vitamin B12 by P. shermanii require neutralization of the accumulated propionic acid to keep the culture growing logarithmically.
(D) The formation of vitamin take place during the later part of the fermentation after the organism approaches maximum growth.
The following statements are describing the production of vitamins through from fermentation of whey. Choose the correct answer from the options given below:
(A) Vitamin B12 production by Propionibacterium shermanii can be done by using several substrates including cheese whey
(B) This organism (P. shermanii) grows aerobically and produces propionic acid, which accumulates in the medium.
(C) Most industrial processes for the production of vitamin B12 by P. shermanii require neutralization of the accumulated propionic acid to keep the culture growing logarithmically.
(D) The formation of vitamin take place during the later part of the fermentation after the organism approaches maximum growth.
(A) Vitamin B12 production by Propionibacterium shermanii can be done by using several substrates including cheese whey
(B) This organism (P. shermanii) grows aerobically and produces propionic acid, which accumulates in the medium.
(C) Most industrial processes for the production of vitamin B12 by P. shermanii require neutralization of the accumulated propionic acid to keep the culture growing logarithmically.
(D) The formation of vitamin take place during the later part of the fermentation after the organism approaches maximum growth.
Show Hint
*Propionibacterium* is anaerobic.
Any statement claiming that it requires aerobic conditions for its primary growth phase is incorrect.
Any statement claiming that it requires aerobic conditions for its primary growth phase is incorrect.
Updated On: Jul 21, 2026
- (A), (B), (C) and (D).
- (A), (B) and (C) only.
- (B), (C) and (D) only.
- (A), (C) and (D) only.
Show Solution
Verified By Collegedunia
The Correct Option is D
Solution and Explanation
Step 1: Understanding the Concept:
Whey is a nutrient-rich by-product of cheese-making containing lactose, proteins, and minerals.
It can be used as a fermentation substrate to produce valuable compounds, such as vitamin \(B_{12}\) (cobalamin), using propionic acid bacteria.
Detailed Explanation:
Let us analyze the correctness of each statement:
- Statement (A): Propionibacterium freudenreichii subsp. shermanii can ferment lactose.
Consequently, deproteinized or whole cheese whey is widely used as a cost-effective substrate for industrial vitamin \(B_{12}\) production.
Thus, Statement (A) is true.
- Statement (B): Propionibacterium species are anaerobic to aerotolerant anaerobic microaerophiles.
They grow anaerobically during the active growth phase, producing propionic acid and acetic acid.
Thus, Statement (B) is false.
- Statement (C): The accumulated propionic acid lowers the pH of the medium, which inhibits bacterial growth.
To maintain logarithmic growth and high cell density, the acid must be neutralized (typically using ammonium hydroxide) to keep the pH around 6.5--7.0.
Thus, Statement (C) is true.
- Statement (D): Vitamin \(B_{12}\) is a secondary metabolite.
Its synthesis occurs primarily during the late exponential and stationary phases of fermentation.
Thus, Statement (D) is true.
Since only (A), (C), and (D) are correct, Option (D) is the correct choice.
Step 2: Final Answer:
The correct statements are (A), (C) and (D) only.
Whey is a nutrient-rich by-product of cheese-making containing lactose, proteins, and minerals.
It can be used as a fermentation substrate to produce valuable compounds, such as vitamin \(B_{12}\) (cobalamin), using propionic acid bacteria.
Detailed Explanation:
Let us analyze the correctness of each statement:
- Statement (A): Propionibacterium freudenreichii subsp. shermanii can ferment lactose.
Consequently, deproteinized or whole cheese whey is widely used as a cost-effective substrate for industrial vitamin \(B_{12}\) production.
Thus, Statement (A) is true.
- Statement (B): Propionibacterium species are anaerobic to aerotolerant anaerobic microaerophiles.
They grow anaerobically during the active growth phase, producing propionic acid and acetic acid.
Thus, Statement (B) is false.
- Statement (C): The accumulated propionic acid lowers the pH of the medium, which inhibits bacterial growth.
To maintain logarithmic growth and high cell density, the acid must be neutralized (typically using ammonium hydroxide) to keep the pH around 6.5--7.0.
Thus, Statement (C) is true.
- Statement (D): Vitamin \(B_{12}\) is a secondary metabolite.
Its synthesis occurs primarily during the late exponential and stationary phases of fermentation.
Thus, Statement (D) is true.
Since only (A), (C), and (D) are correct, Option (D) is the correct choice.
Step 2: Final Answer:
The correct statements are (A), (C) and (D) only.
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