- Penicillium chrysogenum is the primary fungus used in commercial penicillin production because it naturally produces penicillin antibiotic.
- This species was identified as a prolific penicillin producer, leading to its widespread use in pharmaceutical manufacturing.
- Unlike other fungi listed, such as Aspergillus niger or Rhizopus stolonifer, which are used for different industrial applications, P. chrysogenum specifically synthesizes penicillin efficiently.
- This antibiotic is crucial for treating bacterial infections, making P. chrysogenum the preferred organism in penicillin bioprocessing.

Reference: Medical Mycology, Volume 1, Chapter 5