Managing bacteriophage contamination in cheese production:

• Statement (I) is false: Phage rotation is an effective preventive strategy to minimize the build-up of specific virulent phages, but it cannot 'completely eliminate' phage growth, because new virulent mutant phages emerge and environmental contamination persists.
• Statement (II) is true: In commercial cheese factories, defined strain starter rotations are routinely implemented on a daily basis or from vat-to-vat during continuous operation to prevent phage amplification.
  
  Option analysis:
• Both Statement (I) and Statement (II) are true: Incorrect.
• Both Statement (I) and Statement (II) are false: Incorrect.
• Statement (I) is true but Statement (II) is false: Incorrect.
• Statement (I) is false but Statement (II) is true: Correct.

Starter culture protection and maintenance:

• Statement (I) is false: The primary purpose of using protected production systems (such as Lewis systems, Jones systems, or enclosed aseptic vats with HEPA filters and positive air pressure) for bulk starter preparation is specifically to protect against airborne bacteriophages and foreign bacterial contamination, not yeast and mold.
• Statement (II) is true: Bacteriophages are typically host-specific (virulent against only one host strain or specific phage group). Rotating unrelated host strains deprives the phage of its host, thereby preventing phage amplification and avoiding catastrophic starter failure in the dairy plant.
  
  Option analysis:
• Both Statement (I) and Statement (II) are true: Incorrect.
• Both Statement (I) and Statement (II) are false: Incorrect.
• Statement (I) is true but Statement (II) is false: Incorrect.
• Statement (I) is false but Statement (II) is true: Correct.