For production of penicillin using immobilized Penicillium cells in laboratory teaching setups, which medium from the list is most appropriately used as a fungal growth and production medium?

Introduction:
Penicillin is a secondary metabolite produced by Penicillium species under nitrogen-limited, slowly metabolized carbon sources with appropriate micronutrients. Laboratory demonstrations with immobilized cells often use rich fungal media that support growth and subsequent production phases while avoiding media designed primarily for bacterial growth.

Given Data / Assumptions:

• Organism: Penicillium sp. immobilized on a carrier.
• Objective: grow and produce penicillin in a lab-scale setup.
• Media choices include fungal-friendly and bacterial formulations.

Concept / Approach:
Yeast extract is a standard complex nutrient source for fungi, providing amino acids, vitamins, and growth factors conducive to both biomass formation and secondary metabolism in teaching and small-scale experiments. Glucose-only media can repress penicillin synthesis by catabolite repression, while LB broth is optimized for bacteria rather than filamentous fungi. A simple 1% peptone solution is nutritionally limited and not typically the sole medium for penicillin production.

Step-by-Step Solution:

Verification / Alternative check:
Teaching protocols and fungal culture manuals commonly use yeast extract-based media for filamentous fungi in immobilized and free-cell formats; production optimization then adjusts carbon sources away from strong repressors.

Why Other Options Are Wrong:

• 1% peptone medium: Insufficient as a sole production medium for penicillin.
• Glucose medium: Risk of catabolite repression on penicillin biosynthesis.
• LB broth: Formulated for bacteria, not filamentous fungi.

Common Pitfalls:
Assuming a carbon-rich glucose feed boosts antibiotic yield; for penicillin this can do the opposite. Buffering and trace elements also matter for stable production.

Final Answer:
Yeast extract medium