Thermoacidophiles are facultative anaerobic archaebacteira and can tolerate high temperature (`80^@C`) and high acidity (`pH_2`) due to

Options

A. branched chain lipids in cell membrane
B. high KCI conc. and resistant enzymes
C. mucilage covering
D. all of the above.

Answer

To solve the question regarding why thermoacidophiles can tolerate high temperatures (80°C) and high acidity (pH 2), we can break down the reasoning step by step.

### Step-by-Step Solution:

1. **Understanding Thermoacidophiles**:
- Thermoacidophiles are a type of archaebacteria that thrive in extreme conditions, specifically high temperatures and acidic environments. They are classified as extremophiles.

2. **Cell Membrane Composition**:
- The cell membranes of archaebacteria, including thermoacidophiles, contain branched-chain lipids. These unique lipids help maintain membrane integrity and functionality at high temperatures.

3. **Enzymatic Resistance**:
- Thermoacidophiles possess specialized enzymes that are resistant to denaturation at high temperatures. These enzymes allow the organisms to carry out metabolic processes effectively despite the extreme conditions.

4. **Mucilage Covering**:
- Many archaebacteria, including thermoacidophiles, have a mucilage covering or pseudomurein in their cell walls. This covering provides additional protection against environmental stressors, including high acidity and the action of lysozymes, which can damage bacterial cells.

5. **High Potassium Chloride Concentration**:
- The presence of high concentrations of potassium chloride (KCl) in their environment can also contribute to their ability to withstand extreme conditions, as it helps stabilize cellular processes.

6. **Conclusion**:
- Given these adaptations, thermoacidophiles can thrive in extreme environments. Therefore, the correct answer to the question is that their ability to tolerate high temperatures and acidity is due to all of the factors mentioned: branched-chain lipids, resistant enzymes, high KCl concentration, and mucilage covering. Thus, the answer is **"all of the above."**