Question

Given below are two statements:
Statement (I): Culture rotation can completely eliminate phage growth in cheese milk.
Statement (II): Cultures can be rotated on daily basis or after each vat of milk is inoculated.

• A. Both Statement (I) and Statement (II) are true
• B. Both Statement (I) and Statement (II) are false
• C. Statement (I) is true but Statement (II) is false
• D. Statement (I) is false but Statement (II) is true

Hint:

In microbiology, processes can rarely "completely eliminate" viral populations. Rotation schemes are designed to manage and control phage titers below the threshold that causes fermentation failure.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Bacteriophages are viruses that attack and destroy starter culture bacteria, representing the leading cause of fermentation failure in cheese plants.
Detailed Explanation:
Let us evaluate both statements individually:
- Statement I: While culture rotation is a crucial management practice, it cannot completely eliminate bacteriophages from a processing plant. Phages are highly persistent and ubiquitous in the dairy environment. The primary goal of culture rotation is to prevent any single phage population from multiplying to critical levels that would cause starter failure. Thus, Statement I is false.
- Statement II: To control phage populations, dairy plants rotate phage-unrelated starter strains either on a daily basis or after each vat/batch of milk is inoculated. This deprives any emerging phage of its specific host, preventing phage build-up and ensuring consistent fermentation rates. Thus, Statement II is true.
Since Statement I is false and Statement II is true, the correct option is (D).
Final Answer:
Statement (I) is false but Statement (II) is true. Hence, the correct option is (D).