Select the bacteria which converts the ammonia to nitrite ?

Options

A. Nitrobacter only
B. Nitrosomonas and Nitrobacter
C. Nitrosomonas only
D. Nitrosomonas and Nitrosococcus .

Answer

To solve the question of which bacteria converts ammonia to nitrite, we can follow these steps:

### Step 1: Understand the Process of Nitrification
Nitrification is a two-step process in the nitrogen cycle where ammonia (NH3) is first converted to nitrite (NO2-) and then to nitrate (NO3-). The first step is carried out by specific types of bacteria.

### Step 2: Identify the Bacteria Involved
1. **Nitrosomonas**: This bacterium is known to convert ammonia (NH3) into nitrite (NO2-).
2. **Nitrobacter**: This bacterium converts nitrite (NO2-) into nitrate (NO3-), so it does not play a role in converting ammonia to nitrite.
3. **Nitrosococcus**: This bacterium also converts ammonia to nitrite.

### Step 3: Analyze the Options
- **Option 1: Nitrobacter only** - Incorrect, as Nitrobacter converts nitrites to nitrates.
- **Option 2: Nitrosomonas and Nitrobacter** - Incorrect, as Nitrobacter does not convert ammonia to nitrite.
- **Option 3: Nitrosomonas only** - Correct, as Nitrosomonas is the primary bacterium that converts ammonia to nitrite.
- **Option 4: Nitrosomonas and Nitrosococcus** - Also correct, as both convert ammonia to nitrite.

### Step 4: Select the Correct Answer
Since the question asks for the bacteria that converts ammonia to nitrite, the correct answer is **Option 3: Nitrosomonas only**. However, if the question allows for multiple answers, **Option 4** could also be considered correct.

### Final Answer
The bacteria that converts ammonia to nitrite is **Nitrosomonas**.

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