Which of the following enzymes cannot be used for isolation of DNA from Lactobacillus?

Options

A. Lysozyme
B. Protease
C. Cellulase
D. Ribonuclease

Answer

To determine which enzyme cannot be used for the isolation of DNA from Lactobacillus, we can analyze the functions of the enzymes mentioned in the question.

### Step-by-Step Solution:

1. **Understanding Lactobacillus**:
- Lactobacillus is a genus of bacteria that is commonly found in various environments, including fermented foods and the human gut.

2. **Identifying the Enzymes**:
- The question provides four enzymes: Lysozyme, Protease, Cellulase, and Ribonuclease.

3. **Function of Lysozyme**:
- Lysozyme is an enzyme that breaks down the cell walls of bacteria. It is effective in lysing (breaking open) bacterial cells, which is essential for isolating DNA from Lactobacillus.

4. **Function of Protease**:
- Protease is an enzyme that digests proteins. In the context of DNA isolation, it is used to remove proteins that may be bound to the DNA, thus purifying the DNA sample.

5. **Function of Ribonuclease**:
- Ribonuclease is an enzyme that degrades RNA. When isolating DNA, it is important to remove RNA contaminants, and ribonuclease serves this purpose.

6. **Function of Cellulase**:
- Cellulase is an enzyme that breaks down cellulose, a component of plant cell walls. Lactobacillus does not have cellulose in its structure, and therefore, cellulase is not necessary for isolating DNA from this bacterium.

7. **Conclusion**:
- Based on the functions of the enzymes, the enzyme that cannot be used for the isolation of DNA from Lactobacillus is **Cellulase**.

### Final Answer:
The enzyme that cannot be used for isolation of DNA from Lactobacillus is **Cellulase**.

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