Extracellular phenoloxidase activity of micromycetes from various taxonomic groups.

The ability of Micromycetes strains to produce extracellular phenoloxidases was examined on solid malt agar medium using ten different reagents. We established a POx index summarizing the global activity given by the ten reagents used. The results indicated a wide variability depending on the taxonomic groups, the genera and the species. Some groups were relatively homogeneous, either no and low producers of phenoloxidases (Yeasts, Zygomycetes, genera Aspergillus and Penicillium) or medium and high producers of phenoloxidases (Basidiomycetes, Coelomycetes, Tuberculariales and Dematiaceae), while other groups were very heterogeneous (Ascomycetes, Mucedinaceae). The POx index was significantly higher for strains recently isolated than for strains kept in the fungi collection for a long time.