Answer: Penicillium.
- A Penicillium
- B Lactobacillus
- C Rhizobium
- D Saccharomyces
Correct answer: A. Penicillium
Explanation: Penicillin is produced by the mould Penicillium notatum (chrysogenum).
Sewage passes through physical removal (primary), then aerobic biological treatment where microbes form flocs that consume organic matter (secondary); the settled activated sludge is then digested anaerobically to produce biogas - a deliberate switch from aerobic to anaerobic conditions between stages.
Concept context
Microorganisms in food, medicine, sewage treatment, biocontrol, and biofertilizers