The bacterium ( Clostridium botulinum) that causes botulism is

Options

A. a. facultative aerobe
B. an obligate aerobe
C. a facultative anaerobe
D. an obligate anaerobe

Answer

**Step-by-Step Solution:**

1. **Identify the Bacterium:** The bacterium in question is Clostridium botulinum, which is known for causing the disease botulism.

2. **Understand the Characteristics of Clostridium botulinum:**
- It is a gram-positive bacterium.
- It has a rod-shaped structure.
- It is a spore-forming bacterium.

3. **Determine the Oxygen Requirement:**
- Clostridium botulinum is classified as an obligate anaerobe. This means it cannot survive in the presence of oxygen and requires an oxygen-free environment to thrive.

4. **Understand the Implications of Being an Obligate Anaerobe:**
- Obligate anaerobes like Clostridium botulinum are harmed or killed by oxygen. This characteristic is crucial for its survival and growth.

5. **Evaluate the Options:**
- The options provided are:
- A) Facultative aerobe
- B) Obligate aerobe
- C) Facultative anaerobe
- D) Obligate anaerobe
- Based on the characteristics discussed, the correct classification for Clostridium botulinum is "obligate anaerobe."

6. **Conclusion:**
- Therefore, the correct answer to the question is option D: "Obligate anaerobe."

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