The first antibiotic penicillin was isolated from

Options

A. Penicillium notatum
B. P. chrysogenum
C. P.roqueforti
D. P. vermiculatum

Answer

### Step-by-Step Solution:

1. **Identify the Question**: The question asks about the source of the first antibiotic, penicillin.

2. **Recall the Discovery**: Penicillin was discovered by Alexander Fleming in the year 1928.

3. **Identify the Source Organism**: Penicillin was isolated from a fungus. The options provided include various species of the genus Penicillium.

4. **Evaluate the Options**:
- Option A: Penicillium notatum
- Option B: Penicillium chrysogenum
- Option C: Penicillium (generic)
- Option D: Penicillium vermiculata

5. **Determine the Correct Answer**: The correct species from which penicillin was first isolated is Penicillium notatum.

6. **Final Answer**: Therefore, the correct option is **A: Penicillium notatum**.