Which of the following is not a source of restriction endonuclease?

Options

A. Haemophilus influenzae
B. Escherichia coli
C. Agrobacterium tumefaciens
D. Bacilius amyloli

Explanation

To determine which of the following is not a source of restriction endonuclease, we will analyze the options provided.

### Step-by-Step Solution:

1. **Understand Restriction Endonucleases**:
- Restriction endonucleases, also known as restriction enzymes, are proteins that cut DNA at specific sequences. They are often derived from bacteria and are used in molecular biology for DNA manipulation.

2. **Identify Common Sources of Restriction Endonucleases**:
- Common sources of restriction endonucleases include:
- **E. coli**: This bacterium produces several restriction enzymes, such as EcoRI.
- **Haemophilus influenzae**: This organism produces restriction enzymes like HindII.
- **Bacillus amyloliquefaciens**: This bacterium produces restriction enzymes such as BamHI.

3. **Analyze the Given Options**:
- The question mentions **Agrobacterium tumefaciens** as one of the options. This bacterium is known for its role in plant genetic engineering but does not produce restriction endonucleases.

4. **Conclusion**:
- Based on the analysis, **Agrobacterium tumefaciens** is not a source of restriction endonucleases, making it the correct answer to the question.

### Final Answer:
**Agrobacterium tumefaciens is not a source of restriction endonucleases.**