Which of the microrganisms is used for production of citric acid in industries ?

Options

A. Lactobacillus bulgaricus
B. Penicillium citrinum
C. Aspergillus niger
D. Rhizopus nigricans

Answer

To answer the question "Which of the microorganisms is used for the production of citric acid in industries?", we can follow these steps:

### Step 1: Understand the Question
The question is asking for a specific microorganism that is utilized in industrial processes to produce citric acid.

### Step 2: Review the Options
We have four options to consider:
1. Lactobacillus bulgaricus
2. Penicillium citrinum
3. Aspergillus niger
4. Rhizopus nigricans

### Step 3: Analyze Each Option
- **Option 1: Lactobacillus bulgaricus**
- This microorganism is known for producing lactic acid, not citric acid.

- **Option 2: Penicillium citrinum**
- This is primarily known for producing penicillin, an antibiotic, rather than citric acid.

- **Option 3: Aspergillus niger**
- This fungus is widely recognized for its ability to produce citric acid in industrial settings.

- **Option 4: Rhizopus nigricans**
- This microorganism is known for producing alcohol and acetic acid, but not in significant amounts of citric acid.

### Step 4: Identify the Correct Answer
From the analysis, it is clear that **Aspergillus niger** is the microorganism used for the production of citric acid in industries.

### Conclusion
The correct answer is **Aspergillus niger** (Option 3).

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