Bacteria Nitrosomonas converts :

Options

A. `NH_(3)` into Nitrite
B. `N_(2)` into `NH_(3)`
C. Nitrite into Nitrate
D. `NH_(3)` into `N_(2)`

Answer

To solve the question regarding what the bacteria Nitrosomonas converts, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Role of Nitrosomonas**:
- Nitrosomonas is a type of bacteria that plays a crucial role in the nitrogen cycle, specifically in the process of nitrification.

2. **Identify the Process of Nitrification**:
- Nitrification is a two-step process where ammonia (NH3) is first converted into nitrite (NO2-) and then nitrite is converted into nitrate (NO3-).

3. **Recognize the First Step of Nitrification**:
- The first step of nitrification involves the conversion of ammonia (NH3) into nitrite (NO2-), which is specifically carried out by Nitrosomonas.

4. **Evaluate the Given Options**:
- The options provided are:
1. NH3 (ammonia) into nitrite
2. N2 (nitrogen) into NH3 (ammonia)
3. Nitrite into nitrate
4. NH3 (ammonia) into N2 (nitrogen)
- From our understanding, the correct conversion performed by Nitrosomonas is the first option.

5. **Conclusion**:
- Therefore, the correct answer to the question is that Nitrosomonas converts ammonia (NH3) into nitrite (NO2-).

### Final Answer:
- **Nitrosomonas converts ammonia (NH3) into nitrite (NO2-).**