Which of the following used in swiss cheese?

Options

A. Saccharomyces cerevisiae
B. Propionibacterium sharmanii
C. Streptokinase
D. Monascus purpureus

Answer

### Step-by-Step Solution

1. **Identify the Options**: The question presents four options related to the microorganisms used in Swiss cheese production:
- 1. Saccharomyces cerevisiae
- 2. Propionibacterium shermani
- 3. Streptokinase
- 4. Monascus purpurus

2. **Understand the Role of Microorganisms in Cheese Production**: Different microorganisms play various roles in cheese-making. Some are responsible for fermentation, while others contribute to flavor and texture.

3. **Evaluate Each Option**:
- **Saccharomyces cerevisiae**: This is a yeast commonly used in baking and brewing, not specifically in cheese-making.
- **Propionibacterium shermani**: This is a gram-positive bacterium that is specifically known for its role in Swiss cheese production. It is responsible for the formation of holes (or "eyes") in the cheese due to the production of carbon dioxide during fermentation.
- **Streptokinase**: This is an enzyme used in medicine to dissolve blood clots and is not related to cheese production.
- **Monascus purpurus**: This is a mold used in the production of fermented rice products, not in cheese.

4. **Select the Correct Answer**: Based on the evaluation, the correct answer is **2. Propionibacterium shermani**, as it is the microorganism specifically used in the production of Swiss cheese.

5. **Explain the Importance of Propionibacterium shermani**: This bacterium not only contributes to the flavor of Swiss cheese but also plays a crucial role in creating the characteristic holes in the cheese.

### Final Answer
The microorganism used in Swiss cheese is **Propionibacterium shermani**.

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