Q. The percentage of O2 required by moderate anaerobe is
✅ Correct Answer: (C)
2 – 8%
Explanation:
Moderate anaerobes (also called microaerophiles) require low levels of oxygen, typically around 2–8%, for their growth.
- They cannot grow in atmospheric oxygen (~21%) but need some oxygen to survive.
Why other options are incorrect:
- (A) 0%: This corresponds to strict anaerobes that require no oxygen.
- (B) < 0.5%: Too low for moderate anaerobes.
- (D) 5 – 10%: Slightly higher, but generally microaerophiles prefer 2–8%.
Final Answer: (C) 2 – 8%