Intergeneric cosynthesis of penicillin by strains of Penicillium chrysogenum, P. chrysogenum/notatum and Aspergillus nidulans.

A number of mutants impaired in penicillin production have previously been isolated from Penicillium chrysogenum and Aspergillus nidulans. During cofermentation of osmotically fragile mycelia derived from these strains, in the presence of inhibitors of cell wall regeneration, intergeneric cosynthesis has been demonstrated between mutants which are probably impaired in different parts of th penicillin biosynthetic pathway.