Historically, the first penicillin designated “penicillin F” was initially produced using which mold species in early research and production?

Introduction / Context:
Multiple penicillins were identified in early antibiotic research, including penicillin F, G, and others with different side chains and activity. The earliest laboratory and pre-industrial work used strains distinct from later high-yield industrial mutants. This question probes historical knowledge of which mold produced the first recognized penicillin F.

Given Data / Assumptions:

• “Penicillin F” refers to an early penicillin variant identified before large-scale strain improvement.
• Early work primarily involved Penicillium notatum; later industrial production shifted to Penicillium chrysogenum (then extensively mutated/selected).
• Penicillin designations differ by acyl side chain, but the species used historically is the key here.

Concept / Approach:
Penicillium notatum was the original mold from which penicillin substances were observed and studied in the late 1920s and 1930s. As industrialization progressed, producers moved to Penicillium chrysogenum due to superior yields and amenability to mutation/selection (e.g., Q-176, Q-179). Thus, for “first produced” penicillin F, P. notatum is historically correct.

Step-by-Step Solution:
Identify the timeline: discovery and early isolation precede industrial strain improvement.Match early penicillin variants (F among them) to the lab species used then.Recognize that industrial high-yield strains (P. chrysogenum) came later.Select Penicillium notatum as the correct early producer.

Verification / Alternative check:
Historical accounts consistently credit P. notatum with initial penicillin production and observation; later literature documents the shift to P. chrysogenum for yield.

Why Other Options Are Wrong:
Penicillium chrysogenum: dominant industrial species later, but not the earliest lab source of penicillin F.P. chrysogenum Q-176: a selected mutant from much later industrial programs.None of the above: contradicted by the historical record.

Common Pitfalls:
Confusing discovery species with later industrial strains; assuming “first produced” means “highest yield.”

Final Answer:
Penicillium notatum