The organism necessary for conversion of ammonia to nitrite is ...........................

Explanation

To answer the question "The organism necessary for conversion of ammonia to nitrite is ...........................", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Process**: The conversion of ammonia (NH₃) to nitrite (NO₂⁻) is part of the nitrogen cycle, specifically a process called nitrification.

2. **Identifying the Organisms Involved**: Nitrification is carried out by specific types of bacteria. The first step involves the oxidation of ammonia to nitrite.

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