Formation of fertile aerial mycelium within asporogenous streptomycetes as induced by fungal metabolites.

Asporogenous streptomycetes, e. g. Streptomyces flavochromogenes and S. luteolutescens, become able to form fertile aerial mycelium when they are cultivated in close contact with fungi. This may be caused by the production and secretion of fungal metabolites which induce or stimulate the aerial mycelium formation. An attempt was made to characterize the stimulatory factor. Among the numerous fungi tested the most active ones were Cladosporium cladosporioides and Drechslera erythrospila.