Which microbe used as SCP and also reduces environmental pollution?

Options

A. Spirulina
B. Lichens
C. Methylophilus methylotroplus
D. Rhizobium

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a microbe that is used as a Single-Cell Protein (SCP) and also has the ability to reduce environmental pollution.

2. **Identifying Microbes Used as SCP**: Single-Cell Proteins (SCP) are proteins derived from microbial sources, which can be used as food supplements. Common examples include algae, fungi, and bacteria.

3. **Evaluating the Options**:
- **Spirulina**: This is a type of blue-green algae that is rich in protein and is widely recognized for its nutritional value. It is also known to capture carbon dioxide and produce oxygen, thus reducing environmental pollution.
- **Lichens**: These are not single-celled organisms but rather a symbiotic relationship between fungi and algae. They serve as bioindicators of pollution but are not used as SCP.
- **Methylophilus and Methylotroplus**: These are bacteria involved in nitrogen assimilation but are not typically classified as SCP.
- **Rhizobium**: This is a nitrogen-fixing bacterium that benefits soil health but is not used as SCP.

4. **Conclusion**: Among the options, Spirulina is the only microbe that fits both criteria of being used as SCP and having the capability to reduce environmental pollution.

5. **Final Answer**: The correct answer is **Spirulina**.

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