Which bacterium is responsible for oxidation of nitrite to nitrate?

Options

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

Answer

To answer the question "Which bacterium is responsible for oxidation of nitrite to nitrate?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Nitrogen Cycle**:
- The nitrogen cycle is a crucial ecological process that involves the conversion of nitrogen gas from the atmosphere into various forms usable by living organisms.

2. **Role of Nitrogen Fixers**:
- Nitrogen gas (N₂) is fixed into ammonia (NH₃) by nitrogen-fixing bacteria. This is the first stable product in the nitrogen cycle.

3. **Conversion of Ammonia to Nitrite**:
- Ammonia in the soil is converted into nitrite (NO₂⁻) by specific bacteria. The two main bacteria involved in this process are **Nitrosomonas** and **Nitrosococcus**.

4. **Oxidation of Nitrite to Nitrate**:
- The next step in the nitrogen cycle involves the conversion of nitrite to nitrate (NO₃⁻). This oxidation reaction is carried out by a specific bacterium known as **Nitrobacter**.

5. **Conclusion**:
- Therefore, the bacterium responsible for the oxidation of nitrite to nitrate is **Nitrobacter**.

### Final Answer:
The bacterium responsible for the oxidation of nitrite to nitrate is **Nitrobacter**.

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