Magic Mushrooms: Screening for Novel Biocatalysts in the Phylum Basidiomycota

The ascending application of enzymes in organic synthesis creates a growing demand for novel biocatalysts. The applied methods for their identification range from microbial enrichment cultures over metagenome screenings to solely computational methods. In this communication, we demonstrate a straightforward screening approach for the detection of novel biocatalysts in fungi belonging to the phylum Basidiomycota. It basically relies on mincing of the whole fruit bodies of freshly collected mushrooms with subsequent direct screening. Suitability was demonstrated with eight different mushrooms which were investigated for carbonyl reductase activity on sterically demanding carbonyl compounds. The results indicate the presence of potentially useful carbonyl reductases (KREDs) in all tested fungi. Closer characterization of the preparation from pigskin poison puffball (Scleroderma citrinum) showed the presence of KRED exhibiting a broad substrate range. Thus, applicability of this low-tech screening approach could be verified in this study.