An example of Pasteur effect is......

Options

A. Penicillium
B. Pinnularia
C. Saccharomyces
D. Nostoc

Explanation

To solve the question "An example of Pasteur effect is...", we need to understand what the Pasteur effect is and then identify the correct option from the given choices.

### Step-by-Step Solution:

1. **Understanding the Pasteur Effect**:
- The Pasteur effect refers to the phenomenon where the presence of oxygen inhibits fermentation in certain microorganisms. When oxygen is available, these organisms prefer to carry out aerobic respiration instead of fermentation.

2. **Identifying the Process**:
- In the absence of oxygen, certain microorganisms can convert glucose into ethanol and carbon dioxide through fermentation. This is commonly seen in yeast.

3. **Analyzing the Options**:
- The options provided are:
- A) Penicillium
- B) Pinularia
- C) Saccharomyces
- D) No Stove
- We need to determine which of these is associated with the Pasteur effect.

4. **Evaluating Each Option**:
- **Penicillium**: This is a genus of fungi known for producing penicillin but is not primarily involved in fermentation.
- **Pinularia**: This is a less common genus and does not have a significant role in fermentation.
- **Saccharomyces**: This is a genus of yeast that is well-known for its role in fermentation, particularly in the production of alcohol and bread. It is directly related to the Pasteur effect.
- **No Stove**: This option does not relate to the Pasteur effect.

5. **Conclusion**:
- Based on the analysis, the correct answer is **C) Saccharomyces**. This yeast is a prime example of the Pasteur effect, as it exhibits fermentation in the absence of oxygen.

### Final Answer:
The correct answer is **C) Saccharomyces**.