Bacteria which reduce nitrates in soil to nitrogen are:

Options

A. Nitrosomonas
B. Pseudomonas
C. Rhizobium
D. Clostridium

Answer

**Step-by-Step Solution:**

1. **Understanding the Process**: The question asks about bacteria that convert nitrates in the soil to nitrogen. This process is known as denitrification.

2. **Identifying the Bacteria**: Denitrification is primarily carried out by specific types of bacteria. The two key bacteria involved in this process are:
- **Pseudomonas denitrificans**
- **Thiobacillus denitrificans**

3. **Analyzing the Options**: The question may provide multiple-choice options. Based on the information:
- **Nitrosomonas** is not involved in denitrification; it is involved in nitrification (the conversion of ammonia to nitrates).
- **Pseudomonas** (specifically Pseudomonas denitrificans) is indeed involved in denitrification, making it a correct answer.
- **Desulfovibrio** and **Clostridium** are also not primarily known for denitrification.

4. **Conclusion**: Therefore, the correct answer to the question is **Pseudomonas**.

**Final Answer**: The bacteria which reduce nitrates in soil to nitrogen are **Pseudomonas denitrificans**.

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