Question

Given below are two statements:
Statement (I): Multiple strain starter cultures contains more than two organisms in unknown proportion.
Statement (II): Multiple strain starter cultures are more prone to bacteriophage attack than single strain starter cultures.

• 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:

Think of multiple-strain cultures as providing biodiversity. This biological diversity acts as an insurance policy: if a phage kills one strain, other resistant strains are present to complete the fermentation.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Lactic starter cultures are classified based on the number and definition of strains they contain: single-strain, defined multi-strain, or undefined multiple-strain (mixed) cultures.
Detailed Explanation:
Let us evaluate both statements:
- Statement I: Undefined multiple-strain cultures (commonly used for traditional cheese or fermented milk production) consist of a mixture of multiple strains (often more than two strains/species of lactic acid bacteria) whose exact identities and proportions are not known or defined. Thus, Statement I is true.
- Statement II: Single-strain cultures are highly vulnerable to phage attack because if a virulent phage targeting that specific strain enters the plant, it will infect all the cells and cause complete starter failure (slow vat). In contrast, multiple-strain cultures contain different strains with varying phage sensitivity profiles. If one strain is attacked, the other insensitive strains survive and continue the fermentation process, preventing complete starter failure. Hence, multiple-strain cultures are less prone to bacteriophage-induced failure than single-strain cultures. Thus, Statement II is false.
Since Statement I is true and Statement II is false, the correct option is (C).
Final Answer:
Statement (I) is true but Statement (II) is false. Hence, the correct option is (C).