Enhancing production of prodigiosin from Serratia marcescens C3 by statistical experimental design and porous carrier addition strategy

► Maximal prodigiosin production of 7.07g/L by statistical experimental design methodology. ► First report on prodigiosin production (15.6g/L) by addition of porous carrier. ► The fermentation strategy in this study effectively increases prodigiosin production above that achieved elsewhere. Serratia marcescens C3 produces a natural red-pigment, prodigiosin, which exhibits immunosuppressive properties, in vitro apoptotic effects, and in vivo anti-tumor activities. This work seeks to improve the production of prodigiosin by S. marcescens C3 using various strategies. Starch and peptone were identified as the optimized carbon and nitrogen sources for the production of prodigiosin, yielding a prodigiosin concentration of 2.3g/L. This value was significantly increased to 6.7g/L using a carbon/nitrogen ratio of 6/4 (starch/peptone=16g/L/10.67g/L). To enhance prodigiosin production even further, a statistical experimental design methodology was utilized to optimize the composition of the culture medium that is utilized in the production of prodigiosin. Prodigiosin production of 7.07g/L was achieved when the concentrations of two trace compounds, FeSO4·4H2O and MnSO4·4H2O, were optimized using the statistical experimental design methodology. Their optimal concentrations were 0.56mM and 3.25mM, respectively. Ultimately, the production of prodigiosin was increased from 2.3g/L to 15.6g/L, or by a factor of nearly seven by immobilizing microorganisms in 3% calcium alginate beads.