[Isolation and study of the biological properties of a protease biosynthesis stimulating factor in an associative fungal culture].

A factor stimulating the production of exoproteases by Aspergillus kanagawaensis both in a single culture and during combined cultivation with Aspergillus wentii was isolated from the cultural broth of a component in the microbial association according to our scheme. The factor is a pigment of the hydroxyanthraquinone nature. It made the enzyme biosynthesis increase 3.7 times. Its effect on the biosynthesis was compared to that produced by other anthraquinone pigments, viz. alizarin, rubomycin and cinerubins. The compounds stimulated the biosynthesis only 2 to 2.5 times.