One of the following is photosynthetic non-sulphur bacterium

Options

A. Chlorobium
B. Chromatium
C. Rhodospirillum
D. All of theses

Answer

To determine which of the given options is a photosynthetic non-sulphur bacterium, we can follow these steps:

### Step 1: Understand the Types of Photosynthetic Bacteria
- **Sulphur Bacteria**: These bacteria perform photosynthesis using hydrogen sulphide (H2S) as an electron donor. They require light and can thrive in aerobic conditions (with oxygen).
- **Non-Sulphur Bacteria**: These bacteria also perform photosynthesis but do not rely on hydrogen sulphide. They can tolerate low levels of H2S and can grow in both aerobic and anaerobic conditions.

### Step 2: Identify the Options
We need to evaluate the options provided to see which one is classified as a photosynthetic non-sulphur bacterium.

### Step 3: Evaluate Each Option
1. **Chlorobium**: This is a genus of green sulphur bacteria, which means it is a sulphur bacterium. Therefore, this option is incorrect.

2. **Chromatium**: This is also classified as a sulphur bacterium. Thus, this option is also incorrect.

3. **Rhodospirillum**: This bacterium is known to be a non-sulphur bacterium. It can perform photosynthesis without relying on hydrogen sulphide, making it the correct option.

### Conclusion
The correct answer to the question is **Rhodospirillum**, as it is a photosynthetic non-sulphur bacterium.

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