Enhancing Desferrioxamine B production by Streptomyces pilosus through morphological and process optimization using statistical design methods

In this study, Streptomyces pilosus was used to produce Desferrioxamine B (DFOB). To increase DFOB yield, the effects of-yeast extract, MgSO4·7H2O concentration, and different buffer molarities-were assessed using Response Surface Methodology (RSM). The Statistical analysis indicated that all factors significantly influenced DFOB production. Under optimal conditions-yeast extract 15 g/L, MgSO4·7H2O 0.6 g/L, and phosphate buffer 0.0215 M-a maximum yield of 1.55 g/L was achieved, with a productivity of 0.63 g/L·day, the highest DFOB productivity reported in a flask to date. Since oxygen transfer, pH, and medium composition are crucial for improving production, the effects of glucose, yeast extract concentration, and oxygen transfer were studied in a 2-L bioreactor using the Taguchi method (L₉ orthogonal array), with pH maintained at 7.3. Under optimal conditions-glucose 25 g/L, yeast extract 20 g/L, and agitation at 200 rpm with aeration-resulted in 2.35 g/L DFOB, and 0.235 g/L.h productivity, the highest reported in a bioreactor. Field emission scanning electron microscopy (FESEM) analysis revealed that higher agitation rates caused extensive fragmentation of S. pilosus mycelia, reducing DFOB production. This study demonstrates that combining medium optimization and process control can achieve the highest reported DFOB yields, providing insights for industrial-scale production.