Microbe used in cheese preparation is

Options

A. Acetobacter aceti
B. Penicillium notatum
C. Clostridium butylicum
D. Propinibacterium sharmanii

Answer

To determine the microbe used in cheese preparation, we will analyze the given options one by one.

### Step-by-Step Solution:

1. **Analyze Option 1: Acetobacter aceti**
- Acetobacter aceti is a gram-negative bacterium known for converting ethanol to acetic acid. It is primarily used in the production of vinegar, not cheese.
- **Conclusion:** Not the correct answer.

2. **Analyze Option 2: Penicillium notatum**
- Penicillium notatum is a fungus that is famous for being the source of penicillin, the first antibiotic. It is not used in cheese production.
- **Conclusion:** Not the correct answer.

3. **Analyze Option 3: Clostridium butylicum**
- Clostridium butylicum is a bacterium that is important in the synthesis of Vitamin B2 (riboflavin). While it has commercial applications, it is not involved in cheese production.
- **Conclusion:** Not the correct answer.

4. **Analyze Option 4: Propionibacterium shermani**
- Propionibacterium shermani is a bacterium that is specifically used in the commercial production of cheese, particularly in the fermentation process that gives cheese its flavor and texture.
- **Conclusion:** This is the correct answer.

### Final Answer:
The microbe used in cheese preparation is **Propionibacterium shermani**.

---