Allergenic extracts were produced from Drechslera (Helminthosporium) monoceras biomass cultured by solid-state fermentation using wheat bran as the substrate. The main fermentation variables were selected by statistical design, and the optimized biomass yield (1.43 mg/[g of dry substrate . d]) was obtained at pH 9.5 and 45.8% moisture. The allergenic extracts were produced from crude extract by protein precipitation and polyphenol removal. Proteins in the range of 16-160 kDa were identified in the extracts. Their reactions in patients were characterized by in vivo cutaneous tests (positive in 40% of the atopic patients) and by dot-blotting assays.