Prodigiosin production and recovery from Serratia marcescens : process development and cost–benefit analysis

Prodigiosin is a tripyrrole red pigment that has been found to have antimicrobial, anticancer, and immunosuppressive properties. Experiments were conducted in this study to determine the best media types, temperature, and nitrogen and carbon sources for improving prodigiosin intracellular yield in Serratia marcescens . The nutrient broth (NB) medium at 30 °C yielded the highest level of prodigiosin (15 mg/L) when compared to peptone glycerol (PG), tryptone soy broth (TSB), Luria–Bertani broth (LBB), and glycerol beef broth (GBB). Lactose and peptone were found to be the most effective carbon and nitrogen sources, and when added to the nutrient broth, prodigiosin production increased to 18.67% (17.8 mg/L) and 22.67% (18.4 mg/L), respectively. To extract prodigiosin from Serratia marcescens biomass, the best ratio of organic solvent to water (pH 3) was 19: 1, and ethanol was found to be the best organic solvent to extract prodigiosin (15 mg/L) among DMSO, methanol, acetone, acetonitrile, and chloroform. To purify the prodigiosin, a column chromatography study was conducted, with Silica Gel 60–120 mesh as the stationary phase and a solvent mixture of chloroform, methanol, and acetone (4:2:3 v/v) as the mobile phase, yielding a purification yield of 65.39%. The absorption maximum of prodigiosin was found to be 535 nm in a UV–VIS study, and FTIR study confirmed that the functional group of prodigiosin is well matched with prior studies. The eluted fraction of the column contained 100% pure prodigiosin, which was validated by HPLC analysis. The LC–MS analysis also confirmed that prodigiosin was present in the eluted fraction of the column, with a peak at 324 m/z. When compared to the commercial pricing of prodigiosin on the worldwide market, modified media I (nutrient broth with 5% peanut), modified media II (nutrient broth with 5% sesame), and conventional media (nutrient broth) were determined to be economically feasible. The total saleable costs for 1 mg of prodigiosin obtained from modified media I, modified media II, and conventional media are 9229.41 INR (120.68 $), 14,502.66 INR (189.63 $), and 20,301.46 INR (265.45 $) respectively. The economic gain obtained from the modified media I, modified media II, and conventional media was found to be 362.27 $, 293.32 $, and 217.50 $ per mg of prodigiosin respectively.