Production of Acid Proteases -  They include rennin, which is an important enzyme used in cheese production. Many other acid proteases are used in medicines. The important fungal genera producing rennin are Aspergillus, Candida, Coriolus, Endothia and Mucor. Rennin produced by Endothia parasitica was the first rennin marketed commercially in 1967.

The enzyme is excreted out by the fungus in the medium. It is concentrated and precipitated out in an evaporation process.