Antibiotic production by Streptomyces occurs mainly during:
Streptomycetes exhibit biphasic growth kinetics clearly separating primary trophophase from secondary idiophase, a regulatory hallmark crucial for industrial antibiotic production. During logarithmic growth phase when carbon, nitrogen and especially phosphate are abundant, global regulators like DasR respond to N-acetylglucosamine, PhoP to phosphate, and GlnR to nitrogen repressing biosynthetic gene clusters encoding polyketide synthases PKS and non-ribosomal peptide synthetases NRPS to prioritize biomass accumulation, DNA replication and protein synthesis. As nutrients become limiting at onse
Ref: Berdy J Antibiotics 2005 Streptomyces secondary metabolites; Alberts Molecular Biology of the Cell 6th ed. Ch secondary metabolism.
