Nitrobacter

Options

A. Oxidise nitrite
B. Oxidise nitrate
C. reduce nitrite
D. reduce nitrate

Answer

### Step-by-Step Solution:

1. **Understanding Nitrification**:
- Nitrification is a biological process that involves the conversion of ammonia into nitrate through two main steps.

2. **Step 1 - Oxidation of Ammonia**:
- The first step involves the oxidation of ammonia (NH₃) to nitrite (NO₂⁻).
- This reaction is primarily facilitated by bacteria such as **Nitrosomonas** and **Nitrococcus**.

3. **Step 2 - Oxidation of Nitrite**:
- The second step involves the further oxidation of nitrite (NO₂⁻) to nitrate (NO₃⁻).
- This step is carried out by the bacteria known as **Nitrobacter**.

4. **Conclusion**:
- Therefore, Nitrobacter is responsible for the oxidation of nitrite to nitrate in the nitrification process.

### Final Answer:
- The bacteria responsible for oxidizing nitrite to nitrate is **Nitrobacter**.

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