Sustainable production of prodigiosin from rice straw derived xylose by using isolated Serratia marcescens (CMS 2): statistical optimization, characterization, encapsulation & cost analysis

Abstract

Prodigiosin, a pigment renowned for its multifaceted utility in biomedical, nutraceutical, and food domains, encounters impediments stemming from its expensive production process, limited accessibility, and modest yield. To address this challenge, the present investigation centered on the cultivation of naturally isolated Serratia marcescens CMS2, and the primary objective was to fine-tune fermentation conditions employing response surface methodology (RSM) to bolster prodigiosin synthesis. This endeavor leveraged xylose derived from rice straw as an economical carbon source. The cost-effective growth medium was enriched with peanut de-oiled cake, resulting in a remarkable 1.9-fold amplification in prodigiosin output. Under optimized conditions of pH (6.5), substrate concentration (1.5%), inoculum size (1.25%) and agitation rate (150 rpm), 0.5048 color value units per mg of prodigiosin were obtained. The purified prodigiosin underwent a comprehensive characterization utilizing various analytical techniques such as UV-vis spectroscopy, FT-IR spectroscopy, UPLC (ultra-performance liquid chromatography), TLC (thin-layer chromatography), and GC-MS (gas chromatography-mass spectrometry). The UV-vis spectra unveiled a pronounced absorption peak at 535 nm, while GC-MS analysis disclosed a distinctive peak at 324.96 m/z, accompanied by its derivatives. A significant breakthrough was realized when prodigiosin was encapsulated with polysaccharides, resulting in heightened water solubility and an expansion of its potential applications within the food industry. By implementing the cost-effective growth medium developed in this study, a substantial economic benefit of $578.41 was achieved, with the total scalable cost amounting to 8986.84 INR for 1 mg of prodigiosin. These findings position prodigiosin as an economically viable option in a competitive market landscape.