Citric acid is obtained from all, except

Options

A. Aspergillus niger
B. Mucor
C. Yeast
D. Mortierlla

Answer

**Step-by-Step Solution:**

1. **Understanding Citric Acid Production**: Citric acid is a commercially important organic acid that is widely used in the food and beverage industry, as well as in pharmaceuticals and cosmetics.

2. **Sources of Citric Acid**: Citric acid is primarily produced through the fermentation process. The main substrates for this fermentation are glucose and sucrose.

3. **Identifying the Microorganisms**: The question provides four options:
- A) Aspergillus niger
- B) Mucus
- C) Yeast
- D) Mortiella

4. **Analyzing Each Option**:
- **Aspergillus niger**: This is a mold that is well-known for its ability to produce citric acid through the fermentation of sugars. Therefore, it is a source of citric acid.
- **Mucus**: While not a microorganism, mucus can refer to the secretion of certain organisms that may participate in fermentation processes. However, it is not a primary source of citric acid.
- **Yeast**: Yeasts are also involved in fermentation processes and can produce citric acid, especially under specific conditions.
- **Mortiella**: This is a genus of fungi that is not known for citric acid production. Instead, Mortiella has the potential to produce lipids, making it unsuitable for citric acid production.

5. **Conclusion**: Based on the analysis, the correct answer to the question "Citric acid is obtained from all, except" is option D) Mortiella, as it does not contribute to citric acid production.

**Final Answer**: D) Mortiella

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