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

Options

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

Answer

To solve the question "Which of the following enzymes cannot be used for isolation of DNA from Lactobacillus?", we will analyze each of the given options step by step.

### Step-by-Step Solution:

1. **Understanding the Context**:
- The question is about the isolation of DNA from Lactobacillus, which is a type of bacteria. The process of DNA isolation typically involves breaking down cellular components to release DNA.

2. **Analyzing the Options**:
- **Option A: Lysozyme**
- Lysozyme is an enzyme that breaks down the peptidoglycan layer of bacterial cell walls. It is essential for lysing bacterial cells and facilitating the release of DNA.
- Conclusion: Lysozyme can be used for DNA isolation.

- **Option B: Proteinases**
- Proteinases are enzymes that degrade proteins. In the context of DNA isolation, they help remove proteins that are bound to DNA, ensuring that the DNA can be purified effectively.
- Conclusion: Proteinases can be used for DNA isolation.

- **Option C: Cellulase**
- Cellulase is an enzyme that breaks down cellulose, which is a major component of plant cell walls. Since Lactobacillus is a bacterium and does not have cellulose in its cell wall, cellulase is not relevant for isolating DNA from Lactobacillus.
- Conclusion: Cellulase cannot be used for DNA isolation.

- **Option D: Ribonucleases**
- Ribonucleases are enzymes that degrade RNA. During DNA isolation, it is important to remove RNA to avoid contamination. Ribonucleases help in this process, ensuring that only DNA remains after isolation.
- Conclusion: Ribonucleases can be used for DNA isolation.

3. **Final Answer**:
- Based on the analysis, the enzyme that cannot be used for the isolation of DNA from Lactobacillus is **Cellulase (Option C)**.