Particle-based production of antibiotic rebeccamycin with Lechevalieria aerocolonigenes

Abstract

Abstract Rebeccamycin is a promising antibiotic synthesized by the filamentous bacterium Lechevalieria aerocolonigenes. To date, the main investigations were focused on the biological effect or the structure elucidation of rebeccamycin. The aim of this study was to develop an efficient cultivation process based on shake flask experiments. The relationship between morphology and productivity and the positive effects of micro- and macroparticle enhanced cultivation on rebeccamycin production with this strain in the pellet-like morphology was investigated. The addition of talc microparticles increased the rebeccamycin concentration to 120 mg L−1 and 3-fold compared to the control without microparticles. An up to 9-fold increase in rebeccamycin concentration was achieved using surface modified talc particles. Through the addition of glass beads as macroparticles, the highest rebeccamycin concentration of approximately 120 mg L−1 was achieved by the induction of mechanical stress. Cultivation with glass beads enhanced the rebeccamycin concentration 22-fold compared to the control without macroparticles. By further increasing the diameter of the glass beads and increasing mechanical stress, the morphology was driven toward mycelial growth and the productivity was decreased. An adjusted mechanical stress, through the addition of macro-shaped glass bead particles, led to the desired increase in productivity.