Nutrient-deprived growth of streptomycetes reveals a novel growth phenotype with enhanced antimicrobial activity

The capacity of gram-positive streptomycetes to adapt to various environments is reflected in the sheer size of their genomes and the number of encoded regulatory proteins. However, typical studies of Streptomycetes are conducted using media rich in available nutrients. Here, we demonstrate that S. coelicolor colonies respond to nutrient depletion with a phenotype transition. We refer to this phenotype as “foraging growth” for its submerged and continuous growth on depleted media. The foraging phenotype differ distinctly from colonies on nutrient-rich media, in terms of colony morphology, genomic stability and their secretome. The results demonstrate that adaption to nutrient deprivation through foraging is found throughout the phylogeny, indicating it is highly conserved. Furthermore, foraging S. coelicolor gains the ability to inhibit mold on deprived media and exhibits an altered metabolomic profile. An enhanced competitive activity against gram-negative and gram-positive bacteria was also observed among the tested species. These findings highlight the morphological adaptions of streptomycetes during nutrient deprived growth and demonstrate altered secondary metabolite production and that novel antimicrobial activities can be detected.