Find the odd one w.r.t nitrification:

Options

A. Beijerinckia
B. Rhodospirillium
C. Nitrobacter
D. Aulosira

Answer

To find the odd one out with respect to nitrification, we need to analyze the given options and identify which one does not belong to the group of nitrifying bacteria.

### Step-by-Step Solution:

1. **Understand Nitrification**: Nitrification is a two-step process where ammonia is oxidized to nitrite (NO2-) and then to nitrate (NO3-). This process is primarily carried out by specific types of bacteria known as nitrifying bacteria.

2. **Identify Nitrifying Bacteria**: The key bacteria involved in nitrification include:
- **Nitrosomonas**: Converts ammonia to nitrite.
- **Nitrobacter**: Converts nitrite to nitrate.
- **Nitrococcus**: Also involved in the nitrification process.

3. **Analyze the Options**:
- **Baizarinicia**: This is a type of bacteria that is involved in nitrogen fixation.
- **Rhodospirillinum**: This is also a nitrogen-fixing bacterium.
- **Nitrovector**: This bacterium is involved in the nitrification process.
- **Ulcera**: This is known for its role in nitrogen fixation, particularly in rice fields.

4. **Determine the Odd One Out**:
- Among the options, **Nitrovector** is the only bacterium that is involved in nitrification. The other three (Baizarinicia, Rhodospirillinum, and Ulcera) are primarily associated with nitrogen fixation rather than nitrification.

5. **Conclusion**: Therefore, the odd one out with respect to nitrification is **Nitrovector**.