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Progesterone side-chain degradation by some species of Aspergillus flavus group

M E Mostafa1, A A Zohri

  • 1Botany Department, Faculty of Science, Assiut University, Assiut, Egypt.

Folia Microbiologica
|March 29, 2001
PubMed

Insights

Certain Aspergillus flavus group species transform progesterone into valuable steroid compounds like androstenedione and testosterone. These fungi exhibit diverse biotransformation capabilities, aiding in species identification.

Area of Science:

  • Microbiology
  • Biotechnology
  • Biochemistry

Background:

  • The Aspergillus flavus group comprises several species with diverse metabolic capabilities.
  • Steroid biotransformation by fungi is a key area in pharmaceutical and biotechnological research.
  • Understanding the enzymatic pathways involved in steroid modification is crucial for industrial applications.

Purpose of the Study:

  • To investigate the biotransformation of progesterone by various species within the Aspergillus flavus group.
  • To identify the steroid metabolites produced by these fungal isolates.
  • To assess the potential of these species for steroid conversion and their utility in biochemical differentiation.

Main Methods:

  • Seventy isolates from 6 species and 1 variety of the A. flavus group were cultured.
  • Progesterone was incubated with fungal isolates to observe biotransformation.
  • Chromatographic techniques (e.g., HPLC) were employed to resolve and quantify steroid products.
  • Steroid metabolites were identified based on their chemical structures.

Main Results:

  • All tested isolates degraded progesterone, yielding delta 4-androstene-3,17-dione and testosterone.
  • Five species also produced testololactone through ring D opening.
  • Specific hydroxylated metabolites (11 beta-hydroxy-delta 4-androstene-3,17-dione and 11 beta-hydroxytestosterone) were identified in certain species.
  • Progesterone conversion ranged from 60-75%, with significant yields of key steroid products.
  • Aspergillus oryzae and Aspergillus parasiticus showed the highest bioconversion activity.
  • Aspergillus flavus var. columnaris and Aspergillus oryzae yielded the highest amounts of specific steroid metabolites.

Conclusions:

  • Significant species-specific variations in progesterone biotransformation exist within the A. flavus group.
  • The observed biochemical differences can complement morphological and physiological criteria for species identification.
  • These findings highlight the potential of A. flavus group fungi in steroid bioconversion processes.

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