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Fleming's penicillin producing strain is not Penicillium chrysogenum but P. rubens

Jos Houbraken1, Jens C Frisvad, Robert A Samson

  • 1CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, NL-3584 CT Utrecht, the Netherlands;

IMA Fungus
|June 9, 2012
PubMed

Insights

Two species, Penicillium chrysogenum and Penicillium rubens, were identified from the commonly occurring mould Penicillium chrysogenum. Fleming's original penicillin-producing strain is reclassified as P. rubens.

Area of Science:

  • Mycology
  • Microbiology
  • Antibiotic Discovery

Background:

  • Penicillium chrysogenum is a ubiquitous mold found in indoor environments and foods.
  • It is industrially significant for its role in producing the antibiotic penicillin.
  • Previous studies indicated distinct phylogenetic groups within P. chrysogenum isolates.

Purpose of the Study:

  • To resolve the taxonomic status of penicillin-producing Penicillium chrysogenum isolates.
  • To differentiate between closely related species within the P. chrysogenum complex.
  • To clarify the identity of Alexander Fleming's original penicillin-producing strain.

Main Methods:

  • Phylogenetic analysis of key penicillin-producing isolates.
  • Extrolite profiling to identify unique metabolic markers.
  • Re-examination of historical fungal strains and associated documentation.

Main Results:

  • Phylogenetic analysis revealed two distinct, highly supported clades, identified as two separate species: P. chrysogenum and P. rubens.
  • Extrolite analysis demonstrated that P. chrysogenum produces secalonic acid D and F (or lumpidin-related metabolites), which are absent in P. rubens.
  • Fleming's original penicillin-producing strain and the sequenced P. chrysogenum strain were re-identified as P. rubens.

Conclusions:

  • The commonly identified Penicillium chrysogenum is taxonomically resolved into two distinct species, P. chrysogenum and P. rubens.
  • Metabolic profiling (extrolites) provides a key differentiator between these phenotypically similar species.
  • Alexander Fleming's original penicillin-producing strain is confirmed as P. rubens, clarifying historical records.
Keywords:
Flemingindoor mycologyphylogenytaxonomy

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