and Isolated from Soils in Rook () Colonies as Producers of Keratinolytic Enzymes and Mineral Forms of N and S.

Keratinolytic fungi representing the genus that were isolated from the soils of a rook () colony were used as biological agents for the disposal of waste feathers. The aim of this study was to assess the abilities of and fungi with a varied inflow of keratin matter to biodegrade waste feathers. The evaluation was based on the determination of feather mass loss, the activity of keratinolytic enzymes, and the content of mineral N and S forms. It was found that the activity of protease released by the fungi contributed to an increase in the level of soluble proteins and peptides and the concentration of ammonium ions, as well as alkalization of the culture medium. Keratinase activity was significantly correlated with sulfate release, especially in cultures. The strains of fungi isolated from the soil with the highest supply of organic matter, i.e., strains III, IV, and V, had the lowest enzymatic activity, compared to the strains, but they released mineral nitrogen and sulfur forms that are highly important for fertilization, as well as nutritionally important peptides and amino acids. strains can be used for the management of waste feathers that can be applied in agricultural practice.