A good producer of citric acid is

Options

A. Aspergillus
B. Pseudomonas
C. Clostridium
D. Saccharomyces

Answer

To determine a good producer of citric acid from the given options, we can analyze each option based on the information provided.

### Step-by-Step Solution:

1. **Identify the Options**: The options provided are:
- Aspergillus
- Pseudomonas
- Clostridium
- Saccharomyces

2. **Analyze Aspergillus**:
- Aspergillus niger is a type of fungus known for its ability to produce citric acid.
- This microorganism is widely used in the industrial production of citric acid.

3. **Analyze Pseudomonas**:
- Pseudomonas is a genus of bacteria that has various functions, such as oil degradation and nitrogen fixation.
- It is not known for producing citric acid.

4. **Analyze Clostridium**:
- Clostridium is another genus of bacteria, specifically Clostridium butylicum, which is known for producing butyric acid.
- It does not produce citric acid.

5. **Analyze Saccharomyces**:
- Saccharomyces is a genus of yeast, commonly known for its role in fermentation and alcohol production.
- It is not involved in the production of citric acid.

6. **Conclusion**:
- Based on the analysis, the only microorganism among the options that is a good producer of citric acid is **Aspergillus niger**.

### Final Answer:
A good producer of citric acid is **Aspergillus**.

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