Prolific producers of natural products like streptomycetes and myxobacteria live in complex natural frameworks consisting of many microorganisms. Presumably intricate physiological and metabolic regulatory networks have evolved to enable the organisms to respond to intra- and interspecies interactions, e.g. biosynthesis of specific natural products is up-regulated due to competitors in the surrounding area. The soil-dwelling bacterium, Streptomyces coelicolor, produces the biologically-active compound, undecylprodigiosin (Red). Co-incubation with the corallopyronin A-producer, Corallococcus coralloides, was performed to explore the hypothesis that Red production can be enhanced by a myxobacterial competitor. Co-cultivation resulted in earlier onset and increased production of Red (60-fold increase of the intra-cellular concentration). Using different Corallococcus-derived extracts for elicitation, revealed that water-soluble factors triggered the enhanced production of Red which shows antimicrobial, immunosuppressive and anticancer properties.