Investigation of the effect of Streptomyces pilosus morphology and effective factors on desferrioxamine B production based on Taguchi experimental design

In this study, the desferrioxamine B (DFOB) production by Streptomyces pilosus was optimized. First, due to the diversity of bacterial morphology under different operating conditions and its significant effect on DFOB production, the cultivation conditions were optimized to obtain consistent and reproducible inoculum morphology. By examining the impact of four factors—flask type, pH, temperature, and stirring speed—at three levels using the Taguchi method, DFOB production improved from 0.64 to 0.79 g/L with a baffled shake flask, pH 7.3, 150 rpm stirring, and a temperature of 29 °C. Further investigation into culture medium composition, including the type and concentration of carbon source, lysine, and KH2PO4, using the L9 orthogonal array, enhanced DFOB production to 0.9 g/L under optimal conditions. A reduction in iron ion concentration of the culture medium significantly increased DFOB levels to 1.31 g/L. Investigating bacterial growth conditions and DFOB production under optimal conditions in a laboratory bioreactor, while reducing the production process time from 66 to 8 h and without significant changes in biomass, increased the DFOB concentration to 1.5 g/L, which is the highest DFOB production efficiency recorded to date.