Among the investigated filamentous fungi of genera Aspergillus Fusarium, Byssochlamys, Penicillium Paelicomyces and Trichoderma, the strain Aspergillus oryzae A. or./6 was the most suitable for the biosynthesis of protein from starch-containing raw materials. Selection afforded four monocultures characterized by protein increase of 3.1-3.8 g/dm³ , and by protein yield (calculated per utilized starch) ranging from 24.7 to 31.1%: medium utilization fluctuated between 74.0-84.9%.