Relationship between response to and production of the aerial mycelium-inducing substances pamamycin-607 and A-factor.

Respectively, exogenous pamamycin-607 and A-factor restored or stimulated aerial mycelium formation in 30 (67%) and 6 (13%) of 45 Streptomyces strains, and both restored or stimulated it in 5 strains (11%). Pamamycin-607 production was detected in 3 of those strains that responded to pamamycin-607. These findings indicate that pamamycin-607 acts on the common regulatory system for aerial mycelium formation in Streptomyces spp. but is not a universal autoregulator. Increased or decreased antibacterial production occurred in 5 strains in association with aerial mycelium formation by pamamycin-607 or A-factor.